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A Manual of Methods and Procedures for the Regional Waterway Management System By Robert A. Swett David A. Fann Florida Sea Grant University of Florida December 2001 Reviewed March 2008
iii Table of Contents Table of Contents.iii List of Tables ........................................................................................................v List of Fi gures..................................................................................................... vii Abbreviations and Acrony ms...............................................................................ix Acknowled gements..............................................................................................xi Introducti on...........................................................................................................1 The Regional Waterway Management System.................................................1 Waterway Management System Methods.........................................................2 Project Requi rements...........................................................................................3 Personne l..........................................................................................................3 Comput er..........................................................................................................3 Software............................................................................................................4 Differential Global Po sitioning Sy stem..............................................................4 Survey Ve ssel...................................................................................................5 Depth Sounding Equipment..............................................................................5 Tide Level Recorders and Stilling Wells............................................................5 Data Products....................................................................................................6 Project Planning and Preparat ion.......................................................................11 Project Planni ng Map......................................................................................11 Tide Gauge Siting ............................................................................................12 Survey Vessel Outfitting..................................................................................12 Field Proc edures.................................................................................................15 Tide Gauge Inst allati on...................................................................................15 Setting the Tide G auge Data Logger ...............................................................16 Download Data Files....................................................................................18 Transfer Files to a PC..................................................................................19 Equipment Settings .........................................................................................19 GPS Paramete r Setti ngs.............................................................................19 Depth Sou nders...........................................................................................26 Mission Pla nning.............................................................................................27 Field Censuses and Surv ey............................................................................28 Data Dictio naries.........................................................................................28 Boat and Moori ng Cens us...........................................................................28 Signage C ensus..........................................................................................31 Depth Su rvey...............................................................................................32
iv Post-processing of Survey Data..........................................................................39 Tide Correct ions..............................................................................................39 Assigning Parcel Identification Numbers to Boats and Moor ings....................44 Data Cle anup..................................................................................................46 Channel and Boat Restriction Analysis ...............................................................49 Creation of the Traf ficshed Coverage..............................................................49 Preparation of the Channel Centerline Co verage............................................51 Analysis Program............................................................................................53 Products ..............................................................................................................57 Large Format Map Atlases..............................................................................57 Bathymetry Atlas..........................................................................................57 Boat Drafts/Bathyme try/Signs Atlas.............................................................57 Analysis Atlas..............................................................................................57 ArcView Map Atlas Applicat ion........................................................................58 GIS Data Sets and Imager y............................................................................59 Final R eport.....................................................................................................60 Referenc es.........................................................................................................63 Appendice s.........................................................................................................65 Equipment Specificatio ns................................................................................65 Bathy-500MF Multi-Frequency Survey Ec ho Sounder .................................65 Bathy-500MF Transducer (P/N P01540) .....................................................65 Horizon DS150 Singlebeam Echo Sounder ................................................66 Infinities USA Model 220 ultras onic water leve l logger s..............................66 Trimble Pro XR Receiv er.............................................................................66 Trimble DSM212H Integrat ed GPS/MSK Re ceiver ......................................67 AMREL Rocky II Plus..................................................................................68 Dell Dimension XPS T 750MHz Pent ium III..................................................68 Advantage Range Finder.............................................................................69 Survey Tide Corre ction Pr ogram .....................................................................70
vList of Tables Table 1. Survey ve ssel paramet ers.......................................................................5 Table 2: GIS data proj ection param eters..............................................................6 Table 3. HYPACK ge odetic param eters..............................................................34
viiList of Figures Figure 1. Stilling we ll schemat ic............................................................................7 Figure 2. Hydrol ogic areas ..................................................................................12 Figure 3. Bathymetric survey equi pment.............................................................14 Figure 4. Bathy-500MF echo sounder front panel...............................................26 Figure 5. HYPACK geodetic param eters............................................................35 Figure 6. Determining dept h sensor o ffsets........................................................37 Figure 7. Flow diagram of tide correction procedures .........................................40 Figure 8. Traffics hed definitio ns..........................................................................50 Figure 9. Example travel routes in Estero Bay, Lee County, Flor ida...................54
ix Abbreviations and Acronyms AAT Arc Attribute Table AML Arc Macro Language CIR Color Infrared DGPS Differential Global Positioning System DOQQ Digital Orthophoto Quarter Quadrangle ESRI Environmental Systems Research Institute FDEP Florida Department of Environmental Protection FLUCCS Florida Land Use and Cover Classification System FMP Florida Marine Patrol FSG Florida Sea Grant FTP File Transfer Protocol GICW Gulf Intracoastal Waterway GIS Geographic Information System GPS Global Positioning System HDOP Horizontal Dil ution of Precision JPEG Joint Photographic Experts Group LABINS Land Boundary Information System MHHW Mean Higher High Water MHW Mean High Water MLW Mean Low Water MLLW Mean Lower Low Water MSK Minimum Shift Keying MTL Mean Tide Level NAVD88 North American Vertical Datum of 1988 NGS National Geodetic Survey NGVD29 National Geodetic Vertical Datum of 1929 NMEA National Marine Electronics Association NOS National Ocean Service PAT Polygon or Point Attribute Table PDOP Positional Dil ution of Precision PID Parcel Identification Number RTCM Radio Technical Commi ssion for Maritime Services RTL Raster Transfer Language SNR Signal-to-Noise Ratio SSF Standard Storage Format (T rimble Navigation, Inc.) SWFWMD Southwest Florida Wa terway Management District TSIP Trimble Standard Interface Protocol WCIND West Coast Inland Navigation District UF University of Florida USACE U.S. Army Corps of Engineers USCG U.S. Coast Guard USGS U.S. Geological Survey UTC Coordinated Universal Time
xiAcknowledgements Many people have contributed to the philosophy and methods of the Regional Waterway Management System that is embodied within this manual. We would be remiss not to mention their contributions. First and foremost, the combined vision and determination of Dr. Gustavo A. Antonini, Sea Grant Professor Emeritus, and Charles Listowski, Executive Director of the West Coast Inland Navi gation District, led to the concept and subsequent creation of the Regional Waterway Management System. The evolution of their innovative ideas over the past 10 years has led to application of the System in over 1000 miles of wate rways in southwest Florida. Their contributions to Coastal Management in Florida are recognized throughout the state both by their colleagues and by state, regional, and local legislators and coastal managers. The counties of Sarasota, Manatee, and Lee had the foresight to apply the Regional Waterway Management System to their coastal waters. Specific county commissioners championed the implementat ion of the System within their respective counties and provided advice: Commissioner Jack ONeil in Sarasota County, Commissioner Joe McClash in Manatee County, and Commissioner Ray Judah in Lee County. Program administrators for each county were Gary Comp, Sarasota County Natural Resource s Department; Jim Englehardt, Manatee County Human Services Division; and Steve Boutelle, Lee County Division of Natural Resources. The methods contained in the manual have been polished and honed by field staff over the years. Lana Ca rlin-Alexander served as fi eld crew chief for over 3 years and provided many innovative ideas and enhancements. Field technicians who also have contributed include Patricia Knoll, Bob Williams, Ann Brock, Jerry Gibbs, Chuck West, Jerry Wilson, Brad Stephens, Jim Givens, John Henry, and Sharon Schulte, Enhancements to specific methodologic al techniques and field survey procedures have been provided by Cindy Fowler, NOAA Coastal Services Center; Jack Wallace, Senior Hydrographer National Ocean Service; Dr. Donald Sheppard, Bill Miller, and Sydney Schofield of the University of Florida Coastal and Oceanographic Engineering Pr ogram; Evan Brown, previously of the West Coast Inland Navigation District; and Wanda Wooten and Bob Wasno (currently with Florida Sea Grant) of the Lee Count y Division of Natural Resources.
1Introduction This manual details the procedures that are necessary to complete a Regional Waterway Management System for Flori das coastal canals and waterways. The purpose of the Regional Waterway Managem ent System is to provide the West Coast Inland Navigation District (WCIND) and coastal counties with a scientific approach that allows for boat channel ma intenance while protecting resources. The Regional Waterway Management System provides a planning tool that permits managers and policymakers to pr ioritize channel maintenance needs on a regional basis. The Regional Waterway Management System The methodology and objectives of the Regional Waterway Management System stem from a pilot study (Antonini and Bo x 1996) conducted by Florida Sea Grant (FSG) and the West Coast Inland Navigati on District (WCIND) in Sarasota Bay. The pilot study, designed for southwest Flor ida waterways, was a test application of a management system consistent with municipal, county, Florida Department of Environmental Protection (FDEP), and WCIND goals of facilitating safe boating and reducing boating im pacts on natural resources. The design criteria of the Regional Waterway Management System are: (a) fit channel maintenance to boat draft needs; (b) minimize impacts on bay habitats; (c) prioritize and evaluate management alternatives on a regional scale; and (d) identify information products, for boaters and shore resident s, which encourage environmental awareness by users of neighborhood wa terways and boat access channels. Results from the pilot study led to follo w-up studies in south Sarasota, Manatee, and Lee Counties (Antonini, Swett, Schulte Fann 1998; Swett, Antonini, Schulte 1999; Swett, Fann, Antonini, Carlin Alexander 2000, 2001). Waterway Management System results provide Fl orida counties with a rationale and method for implementing a Regional Wate rway Management System containing the following elements: (a) documentation of existing depths; (b) establishment of maintenance dredging requirements accordi ng to user draft specifications; (c) placement of signs to conform with boat density and traffic patterns; (d) management of boat traffic based on detail ed knowledge of boat distributions and travel routes; (e) siting of habitat restoration to protect waterways; (f) regional scale permitting to accommodate water-dependent uses and to minimize environmental impacts; and (g) educating the public, using waterway maps and guide materials, to instill stewardship and best boating practices. A Memorandum of Agreement (MOA), signed by the FDEP, FSG, and the WCIND (September 26, 1997), provides the required, state-approved framework for a Regional Waterway Management S ystem that is needed to implement the study results.
2Waterway Management System Methods The implementation of a Regional Wate rway Management System consists of five broad work phases, which include: 1) pr eparation, 2) field surveys, 3) postprocessing, 4) data analysis, and 5) dev elopment of the final products. The preparatory phase includes such components as gathering necessary data and map materials, hiring and training ne w personnel, acquiring and configuring equipment, and determining the location and extent of waterways to be included in a waterway management project. Boat channels are identified by interpretation of section aerials, by field reconnaissance, and by tapping local knowledge of the study areas boaters; wher ever present, permitted and non-permitted channel markers are used to guide channel identification. Two field censuses and one field survey are conducted along salt-water accessible canals and waterways using a Di fferential Global Positioning System (DGPS) to map features of interes t. Geographic locations and attributes are logged for boats; boat locations (moori ngs), whether occupied or vacant; derelict vessels; boat-related signs; and channel centerline depths. Post-processing includes cleaning t he boat/mooring and sign census data, cleaning the depth survey data, correcti ng survey depths to a standard datum, such as the Mean Lower Low Wate r (MLLW) tidal datum, and transferring property information to each boat and mooring feature. Data analysis consists of correcting depths to MLLW using tide gauges installed at appropriate locations throughout the project area. An Ar cInfo Arc Macro Language (AML) application determines channel restrictions and boat accessibility levels from the field data. Final products include three sets of large-scale (1:2400) map atlases, an ArcView Map Atlas application, a CD contai ning primary and secondary Geographic Information System (GIS) data layers provided in an ArcView application, and a final report that includes a prioriti zation of maintenance alternatives.
3Project Requirements Personnel The application of the Waterway Managemen t System involves a wide variety of tasks and functions. Different software pa ckages and specialized equipment are used during each project phase, and they require personnel with a high level of expertise. Furthermore, during each impl ementation of a Regional Waterway Management System, unique sit uations arise that require project personnel to devise innovative solutions. Fieldwork includes a bathymetric survey a boat and mooring census, and a sign census. All three require a vessel oper ator with good seamanship, navigation, and safety skills. Field personnel should have detailed local knowledge of the waterways within the project area. In par ticular, the person who conducts the bathymetric survey should (a) be very fam iliar with preferred travel routes, shoal locations, and local boating patterns and behaviors and (b) be prepared to observe and consult boaters encountered duri ng the survey to identify waterways actually used. The person who conducts the boat census s hould have good boat identification skills, including the abilit y to identify vessel types and determine their characteristics: such as make/model, draft and length. Field personnel, excluding the boat operator, should have good computer skills, or they will need to be trained. Skills required include familiarity with the computer systems and the various software packages discussed below. Furthermore, field personnel should have In ternet familiarity, including the ability to use e-mail and FTP in order to communi cate with other project personnel. The persons who conduct the fieldwork shoul d have an understanding of the basic principles of DGPS, including knowled ge of the various parameters and settings that are necessary to assure surv ey accuracy and quality. These will be discussed in a subsequent section. Formal in struction in the use of DGPS, such as the course needed to obtain Trimble DGPS operator certificat ion, is desirable. Computers The number of computers required to accomplish project tasks will depend on the scope of each particular waterway management project that is undertaken. In general, computers will be needed for field and office personnel responsible for processing project data. Co mputer related tasks associated with past waterway management projects have been performed on desktop and laptop computers running several versions of the Micr osoft Windows operating system, including 98, NT, and 2000. The Arc Macro Language (A ML) program that determines boat accessibility levels and channel restrictions is designed to run on a Sun Solaris system with UNIX ArcInfo. S pecifications are given below for the computer equipment used by FSG to implement waterway management projects at publication time. In general, higher end systems should be used to implement future projects.
4 Field operations, particularly the bathy metric survey, are accomplished using a Rocky II+ ruggedized notebook fr om AMREL Systems, Inc. This notebook is designed for field and in-vehicle applications. The laptop is certified to the MILSTD 810C and E1 standard and is rain, temperature, shock, vibration, salt fog, and humidity resistant. Computers used fo r office related tasks include two systems: 1) a Dell Dimension XPS T750r 750 MHz Pentium III with an 18GB SCSI hard drive, and 2) a Sun Ultra II system running Solaris 2.5. Complete specifications for project equipment are contained in the Appendix. Software The software programs listed below are used during various project phases. 1. ESRI ArcInfo 8. x for Workstation 2. ESRI ArcInfo 7.2 for Solaris 3. ESRI ArcPress for Solaris 4. ESRI ArcView 3.x 5. SURVCORR and BASELINE2tide co rrection programs (supplied on accompanying CD-ROM) 6. Microsoft Excel 7. Microsoft Access 8. Microsoft Word 9. Adaptec Easy CD Creator 10. Trimble Pathfinder Office 2.51 11. Trimble Asset Survey Software 12. Trimble TSIP TALKER (version 2.0) 13. E-mail and FTP software 14. Compression software (e.g., WinZip) Differential Global Positioning System The Regional Waterway Management S ystem, as designed, is intended as a planning tool. However, t he bathymetric survey procedures and methods meet Class 1 standards as described in the U.S. Army Corps of Engineers (USACE) Hydrographic Survey Manual (U.S. Army Corps of Engineers 2001) and hydrographic survey specifications of the National Ocean Service (National Ocean Service 1999). Two code phase DGPS units are used to reco rd horizontal positions: 1) a Trimble Pro XR DGPS with a TSC1 data logger and a radiobeacon receiver is used for the boat and signage censuses, and 2) a Trimble DSM212H GPS receiver with an integrated MSK dual-channel receiver with EverestTM technology2 is used for 1 Rated for shock, vibration, temperature (operating0o C to 50o C; storage0o C to 60o C), humidity (85-95% RH), rain (4 in./hr/ 0.54.5 mm/drop 30 min. period), salt fog (35o C 5% 48 hour period), and altitude. 2 Everest technology improves results in high multipath environments and locations where other radio frequencies could jam the GPS signals.
5 the bathymetric survey. Under optimum conditions, the horizontal accuracy (RMS) for both GPS units, using the RTCM radiobeacon transmissions, is 50 cm + 1 ppm on a second-by-second basis, wh ich, for the 4-county area of the WCIND, is better than 1 meter (Trimb le Navigation Ltd. 1998b). Under normal operating conditions the horizontal accuracy for 95 percent of feature positions is expected to be 2 meters or less, wh ich conforms with USACE and National Ocean Service (NOS) accuracy standards An Advantage Range Finder from Laser Atlanta measures feature offset s during the boat and sign censuses. Survey Vessel In order to provide background on su itable vessel types needed to complete fieldwork, a description of vessels used during recent projects follows. The first vessel, a Key West model 1720, is an open fisherman with a shallow V fiberglass hull and a center console. The Key West has a 70hp, 4-stroke, Evinrude outboard and a fuel capacity of 31 gallons. The second vessel, a Boston Whaler 130 Sport, is an open sport with a side console and a tri-V fiberglass hull. The Whaler has a 25hp, 4-stroke, Mercur y outboard and a fuel capacity of 6.6 gallons. The physical characteristics of each vessel are found in Table 1 below. Table 1. Survey vessel parameters. Key West Boston Whaler Length 17 2 13 3 Beam 6 10 5 11 Weight (lb) 1050 600 Draft 8 7 Depth Sounding Equipment Sounding equipment consists of a Ba thy-500MF multi-frequency, single-beam echo sounder (Ocean Data Equipment Corporation); a Standard Horizon DS150 single-beam echo sounder (Standard Co mmunications); and a fiberglass sounding pole, calibrated and marked at 0.01-foot intervals (see Appendix for equipment specifications). Soundings from the Ba thy-500MF and the DS150 are passed to HYPACK Max hydrographic survey software (Coas tal Oceanographics, Inc.) loaded on the AMREL Rocky II+ notebook computer. The s ounding pole is used to verify any suspect echo sounder readings and to check depths in shallow areas (below 3 feet). Calibration of the depth sounders is accomplished using a bar, which consists of a 1.25 ft. X 2.9 ft. lead-weig hted aluminum plate. The bar is lowered below the transducer with a 25-foot long, 1/8-inch diameter twis ted stainless steel wire cable marked at 5-foot interv als, from 5 feet to 20 feet. Tide Level Recorders and Stilling Wells Tide observations are necessary to corre ct soundings to chart datum (MLLW). Tide level recorders consist of Model 220 solid-state, ultrasonic fluid level sensors manufactured by Infinities USA, Inc. (see Appendix for equipment
6 specifications). Each Model 220 data logger stores 3,9 06 records, which allows for 16 days of tide data at a logging inte rval of 6 minutes. Data files can be downloaded, in the field, to a laptop computer or an HP-48GX calculator and examined for integrity. Each gauge is mounted on a st illing well, the dimensions of which are shown in Figure 1. All sections of the stilling well are cemented t ogether except for the cap, which is secured to the closet flange usi ng two padlocks to protect the tide level recorder. The stilling well is secured to a piling using wooden I-beam mounts and stainless steel worm gear clamps. Data Products Several GIS data themes need to be obtai ned or created duri ng the preparatory phases of the waterway management project. These data sets must meet project currency requirements and they must cover the geographic extent of the project area. Required data include background imagery, exis ting USACE bathymetric surveys, seagrass and mangrove cove rages, salt-water accessible parcel boundaries and attribute information (parce l identification number, owner, and address), and vertical benchmark locations and attributes. Each data set is described below. The Albers equal-area3 projection is the recommended projection system for the waterway management project. At present, most third-party data sets necessary to complete the project are distributed in this format. Table 2 lists the projection parameters. Table 2: GIS data projection parameters. Projection Parameters Projection Albers Units Meters Datum HPGN (or NAD83) 1st standard parallel 240 00 00 2nd standard parallel 310 30 00 Central Meridian -840 00 00 Latitude of projection's origin 240 00 00 False easting (meters) 400000.0 False northing (meters) 0.0 3 Equal-area means that a spatial unit of set si ze, when placed on different parts of a map, will cover exactly an equal area of the actual earth, no matter where on the map the unit is placed. Although neither shape nor linear scale is truly co rrect, the distortion of these properties is minimized in the region between the standard parallels.
7 Figure 1. Stilling well schematic.
8 U.S. Geological Survey (USGS) Dig ital Orthophoto Quarter Quadrangles (DOQQs) are recommended for use as background imagery during all project phases. This imagery is readily availabl e for all areas of Florida and can be obtained in JPEG image compression format, at resolutions of 1, 2, and 3-meter, from the web site maintained by the Land Boundary Information System (www.labins.org ). DOQQs combine the image characterist ics of a photograph with the geometric qualities of a map. Image di splacements caused by camera tilt and terrain relief are removed, so that ground features are displayed in their true ground position. This allows for the direct measurement of distance, areas, angles, and positions. Furthermore, a DOQQ displays features that may be omitt ed or generalized on maps. The DOQQs used for past waterway management projects in southwest Florida are based on 1994-95, 1:40,000-scale Color Infrared4 (CIR) photography. USACE bathymetric surveys have been used during past projects to complement data collected by FSG or to provide data for areas not surveyed by FSG, such as the Gulf Intracoastal Waterway (GICW). A point of contact, to determine the availability and characterist ics of USACE survey data, is the ConstructionOperations Division of the Operat ions and Maintenance Technical Support Section of the USACE (904-232-1132; P.O. Box 4970, Jacksonville, FL 322320019). Seagrass, mangroves, and land use/land cover normally are extracted from databases obtained from third parties, such as Floridas Water Management Districts. For example, the Southwes t Florida Waterway Management District (SWFWMD) has ArcView shapefiles of seagra ss for the years 1982, , , and The seagrass beds were interpreted from 1:24,000 natural color aerial photography. The spatial extent of the SWFWMD seagrass GIS databases varies from year to year, but generally extends from Tampa Bay to Charlotte Harbor. Mangroves normally are extracted from a land use/land cover GIS database that is categorized according to the Florida Land Use and Cover Classification System (FLUCCS) (Florida Bureau of Comprehensive Planning, 1976) and whose features were photo-interpre ted from 1:12,000 USGS CIR DOQQs. SWFWMD GIS databases are available for download from: www.swfwmd.state.fl.us Parcel boundaries and pr operty appraiser data may be obtained from the appropriate local or regional agency. Ideally, parcel boundaries are available as ArcView polygon shapefiles in the Albers pr ojection. If not, they will need to be converted to a shapefile and re-project ed. The parcel boundary GIS file should contain the parcel identification number (PID) in the theme attribute table. The 4 Color infrared photography differs from conventional color film because its emulsion layers are sensitive to green, red, and near-infrared radi ation (0.5 micrometers to 0.9 micrometers).
9 PID enables linkage of the par cel boundary file to inform ation contained in the property appraiser database. Property apprai ser data should be obtained for the parcels within the study area and fields should include parcel owner name and address. Vertical benchmark information is obtai ned from several sources, starting with local offices of city and county surveyors. A number of web sites maintained by state and federal agencies contain detai led benchmark information. The LABINS web site (www.labins.org ) contains databases with information on horizontal and vertical benchmarks, including the Na tional Geodetic Survey (NGS) database and USGS 3rd order vertical data. The National Ocean Service (NOS) (www.ngs.noaa.gov/datasheet.html ) allows retrieval of NGS data and NOS tidal benchmark information via interactive m ap, permanent identif ier, radial or rectangular search, station name, project identifier, or USGS quad name. USGS tide gauges and associated benchmarks are si tuated in a number of locations throughout the state and their location and st atus is recorded in the USGS Water Year reports. Contact the USGS to dete rmine their availability and suitability for project requirements.
11Project Planning and Preparation Project Planning Map The field crew requires a map of the st udy area that delineates the salt-wateraccessible canals, channels, and other waterways where boats, moorings, derelict vessels, and signs are to be tallie d and where depths are to be surveyed. A copy of the map should be made for each field census and survey to help plan and monitor fieldwork progress. For pas t waterway projects USGS 1-meter DOQQs were used as the map base. Map production is best accomplished in GIS software, such as ArcView. A perm anent ArcView Project file should be created so that future m odifications or additions can be readily incorporated. The planning map includes several GIS themes, most important ly the location and extent of channel centerlines thr oughout the study area. The overview provided by the planning map will help to plan the work schedule, monitor field progress, and annotate areas as they are complet ed. As each segment of fieldwork is completed, the resulting data should be mapped in the GIS to ensure that no data gaps exist. The planned waterway centerlines are best drawn by persons with knowledge of travel routes actually used by boaters. The county or regional agency that is charged with waterway management within the project area should oversee this procedure. For example, during project implementation in Lee County, personnel from the Marine Services Program, a section of the Division of Natural Resources, determined the extent and location of channels to be included. The resultant map is deemed pre liminary, as the field cr ew will update it during the surveys. Field personnel should, as necessary, consult knowledgeable shore residents and observe actual boat travel routes. Other themes included on the planning map are the loca tions and characteristics of signs, vertical benchmarks, hydrologic ar eas, tide gauges, locks, boat lifts, etc. Depending on project circumstances, additi onal map themes may be helpful. The sign census is conducted first and the resulting GIS theme included on the planning map for the depth survey. Vert ical benchmarks can be categorized by their source, such as marks from the ci ty or county, LABINS NOS, or USACE. Hydrologic areas are delin eations drawn by projec t personnel to guide the placement of tide gauges and the schedul ing of depth survey work. Their inclusion on the planning map is important in complex areas, as exemplified by the City of Cape Coral (Figur e 2). In less complex situations, hydrologic areas may be unnecessary. The map should inclu de planned tide gauge sites (see Tide Gauge Siting) and gauges that are maintai ned by other agencies, such as the USGS.
12 Figure 2. Hydrologic areas. Tide Gauge Siting During collection of bathymetric data, t he water surface elevation relative to mean lower low water (MLLW) will vary wit h local tides, freshwater flows, and environmental effects (e.g., wind). To correct for these effects, all bathymetric data are collected near a gauge or betw een pairs of gauges. Gauge sites are selected in accordance with NOS and USACE standards required for tidal correction of bathymetric data (National Ocean Service 1999; U.S. Army Corps of Engineers 2001). The spatial distribution of project tide gauges is determined in consultation with qualified personnel5 using the mapped hydrologic areas to guide gauge siting. Additional factors considered for gauge locations include safe, secure sites, and the availability of nearby monuments of known elevation, to which gauges can be referenced. Survey Vessel Outfitting Survey equipment needs to be securely mounted on the vessel before initiating fieldwork (Figure 3). The exact locati on that equipment is mounted will depend on the particular vessel used for the surv ey and on the positioning of personnel during the survey. Though the survey equipment, which was described previously, is designed for foul weather conditions, precautions should be taken to protect the equipment from incl ement weather and salt spray. 5 Dr. D. Max Sheppard, Professor in the Univ ersity of Florida Coastal and Oceanographic Engineering Program, provided guidance on tide gauge siting in several study areas.
13 Currently, a 17-foot Key West is used for the bathymetric survey (Figure 3G). An explanation follows on how the equipment was mounted on the Key West, in order to guide the placement of sounding eq uipment on other vessels. A special side mount for the Bathy-500M F transducer fits in a r od holder on either the port or starboard side (Figure 3A). The DGPS antenna is attached directly above the transducer mount and, thus, directly ov er the Bathy-500MF transducer (Figure 3A and C). A bulkhead mount holds the Bathy-500MF instrument on the inside, forward, port side (Figure 3D); a custom fabric cove r protects the Bathy-500MF from spray. The DSM212H DGPS is mounted on the inside back cover of the Bathy-500MF. The Horizon DS150 trans ducer is transom mounted and the DS150 display unit is placed on the console, visible to the boat operator. A fighting chair for the equipment operator, forward of t he console, replaces the original passenger seat cushion (Figur e 3E). A swivel mount, adapted from a commercial monitor stand, holds the AMREL laptop forward of the chair (Figure 3B). This mount is bolted to the aft bul khead of the foredeck. A custom canvas dodger, with a roll-up clear plastic forward window, protects the entire work area from spray and rain and provides shade that improves the laptop computer display visibility (Figure 3G). Two custom 12V outlets, in addition to t he cigar lighter on the console, provide power for the survey equipment. A dual-battery system, with a second battery added in parallel with the original boat ba ttery, has proven a reliable source of clean instrument power. The Trimble Pro XR DGPS, the TSC1 data logger, a radiobeacon receiver, and the Laser Atlanta rangefinder are used for the boat/mooring and sign censuses. The census taker sits in the captain s chair, adjacent to the DGPS antenna, which is mounted in a rod holder. A maintenance schedule needs to be established and followed for each of the survey vessels. Each day the vessel should be secured and all survey equipment removed. During the bathymetric survey, it is important that fuel be kept within a certain range to insure that the load conditions do not vary from one extreme to another, thus affecting the static draft. In order to minimize travel time, suitable locations to overnight the boat should be found. This will require locating willing lo cal residents. Likewise local residents with appropriate facilities should be found for mounting tide gauges on docks. (A productive way to find such volunteer participants is through organizations such as boating clubs.) Key site criteria include security for the boat and tide gauges, as well as accessibility by the field per sonnel. Prior permission must be obtained to access the tide gauge or use the dock when no one is home.
14 Figure 3. Bathymetric survey equipment.
15 Field Procedures Tide Gauge Installation Once appropriate tide gauge sites are established (see Tide Gauge Siting), secure facilities need be found where gauges can be installed. Experience has shown that the best location is a dock at a private residence, as it provides greater security. Each proposed gauge si te should be visited to confirm the presence of vertical benchmarks and thei r suitability to determine tide gauge elevation. Ideally, benchmarks are located within sight of the tide gauge installation, such as on a seawall or on an adjacent road or structure. If no suitable benchmarks ar e found in the vicinity of the gauge site, then a licensed surveyor must establish benchmark (at least 3rd order), or another gauge site needs to be selected. Naturally, property owners must give permi ssion to install gauges on their docks. Tide gauge stilling wells must be securely fastened to a protected piling or other suitable mounting location (Figure 3F). Stainless steel straps, similar to automotive hose clamps, but available in lengths of 4 feet or longer, have proven a satisfactory means. Straps with thread sl ots over most of their length, rather than just near the tip, ar e preferable, as they accommodate a wide variety of dock piling diameters. An I-beam of 2 x 4 lumber, se curely screwed together and placed between the stilling well and pili ng, provides a stable mount with a suitable standoff distance. The field crew must carefully monitor the gauges elevation relative to the piling to check for vertical slippage or other problems. The elevation of installed gauges, rela tive to NGVD29 or NAVD88, can be determined by differential leveling conducted by projec t personnel. If the benchmark is located on a seawall, t hen simultaneous measurements to the water surface from both the gauge and benc hmark are used to establish gauge elevation. The average of three or more measurements, made under calm conditions, is used to establish the gauge elevation. From ot her benchmarks, not located on seawalls, the gauge elevati on can be established via differential leveling. The MLLW tidal datum is determined in reference to historical NOS tidal benchmarks located in the vicinity of the gauge. The NO S tidal benchmark sheets, in many cases, provide elevations of tidal and geodetic datums referenced to MLLW (feet). The following example is for a historical NOS tide gauge that was located on the Peace River:
16 HIGHEST OBSERVED WATER LEVEL = 3.85 MEAN HIGHER HIGH WATER (MHHW) = 2.24 MEAN HIGH WATER (MHW) = 1.93 MEAN TIDE LEVEL (MTL) = 1.17 NATIONAL GEODETIC VERTICAL DATUM-1929 (NGVD) = 0.56 MEAN LOW WATER (MLW) = 0.41 MEAN LOWER LOW WATE R (MLLW) = 0.00 LOWEST OBSERVED WATER L EVEL (01/16/1972) = -2.72 Tidal benchmark sheets may be obtai ned from the following NOAA web site: http://co-ops.nos.noaa.gov/bench.html Supplemental water level data may be obtained from USGS water-stage recorder s when located within project areas. During installation of the tide gauge, reco rd all critical parameters on the Gauge Installation Form, which can be found on the accompanying CD-ROM (/FieldProcedures/TideGaugeInstallationFo rm.doc). Information recorded on this sheet includes benchmark characteristi cs and a record of the procedures and measurements obtained during tide gauge calib ration and leveling procedures. This information is of vital importance when correcting depth measurements to the MLLW tidal datum. Tide corrections are performed by means of a computer program, Survey Tide Correction (SURVCORR.exe), developed by the University of Florida (UF) Coastal and Oceanographic Engineering program. SURVCORR was developed to correct depths within a winding canal or river system. The program, with inputs of spatially referenced soundings and tide gauge readings, determines and applies depth corrections based on time and relative location. Tide data are interpolated to each centerline, or us er-constructed baseline point, by assuming a linear variation of the tide through the system. Weighting the interpolation by the distance from a gauge provides correct ion for non-linear effects, such as viscous dissipation. A more detailed de scription of the progr am can be found in the Appendix (see Survey Tide Correction Program). Setting the Tide Gauge Data Logger After the tide gauge stilling well is secured in its operating position and nearby benchmarks identified to serve as elevat ion references, set (program) the data logger, in accordance with the Infinities user manual (Infinities USA, Inc. 1999). The logger can be set using either a laptop computer or a HewlettPackard HP48GX calculator. A laptop PC is faster, and its software is considerably more userfriendly. However, the HP48GX is much handier in the field and is usually the interface device of choice. Th e following paragraphs summarize the procedure for setting a data logger with the handheld calculator.
17 Before beginning fieldwork, load the Infi nities software into the HP48GX. The Infinities user manual expl ains this rather complicated process in detail. For stepbystep help, call Infinities USA at 1-888-808-5488. (Important: A special version of the Infinities data logger so ftware, included on the accompanying CD, allows use of the Offset field to tag a sitespecific numeric identifier code to each data record. If the standard Infinities software is used instead, the numeric value of the code entered will be added to each record! The site code will stay the same until the logger is reset at a different site.) Se t the calculators internal clock. (Experience has shown it advisab le to set all system clocks to UTC.) Before installing the special version of the Infinities data logger, decompress the three disk images on the CD-ROM to 3-1/2 inch floppies (/FieldProcedures/InfinityGauge/Disk1 .zip, Disk2.zip, and Disk3.zip). Setting the data logger and downloading dat a are done via the HP serial cable purchased with the calculator. First, tu rn on the HP48GX and then insert the cable into the calculators top 4pin socket. Be careful; the socket pins are easily bent. Connect the 9pin connector on the other end of the cable to the data logger. Navigating the HP48GXs keyboard is best d one at first with the Infinities manual on hand, as each key has multiple functi ons. To set the data logger, select Set Datalogger from the Datalogger Star t Menu and then choose Reset Auto Set. Enter a threedigit identifier code number for the station and press the OK soft key (the key below the desired choice in th e calculators display). It is best to enter the station codes for a study area with large numbers, such as 100, 101, etc., rather than 001. Then, if an HP48GX with the standard Infinities software is inadvertently used, and the code is added to the depth readings as an offset, the large resulting error will be immediately obvious. The Time to Begin display will appear. Enter the number of days (zero), hours, minutes, and seconds (zero) from 12AM to the desired first sounding time. For a 6-minute logging interval, choose to start at 0, 6, 12, 18or 54 minutes after the hour. (The software uses a 24-hour clock system .) As an example, if the present time is 3:08PM, enter zero days, 15 hour s, 12 minutes, and zero seconds to start the logger at 3:12PM (1512 in the 24hour system), the next appropriate logging time for a 6minute interval. Press OK w hen the setting is correct, and enter the Time Interval Between Readings in hours (zero), minutes (6), and seconds (zero). Press OK to return to the Datalogger Start Menu. Make several data logger readings and nearly simultaneous staff gauge or tape measure determinations of drop to the water surface from the stilling well rim (which corresponds to the loggers transducer height). This can be done by waiting for the logger to make its sc heduled readings every six minutes. A more efficient method is to select Current St atus from the Data logger Start Menu, which will cause the logger to immediat ely take and display a reading. (This special reading is not stored in the logger memory, so it will not appear in downloaded data files.) Record and compare the readings. If the logger sounding
18 error exceeds the specified limit (1 perc ent of reading), calibrate the logger, using the loggers built-in calibration routine, and then repeat the measurements. To calibrate the logger, select Calibrate Logger from the Datalogger Start Menu and enter a depth reading and its correspondi ng manual measurement. Then take a couple of additional test readings to veri fy the calibration reduced the error to within the specification. Scroll down to Name & Message on the Da talogger Start M enu to enter a name for the station (8 characters maximum) and, if desired, additional text (up to 31 characters). This information will appear in the headers of downloaded data files, butunlike the threedigit numeric stat ion code entered earlierit is not tagged to each data record. When the data logger is corre ctly programmed, wait for a least one scheduled reading to be taken, and download it as described in the next section. If the reading is on time and appears reasonable, the logger is running and collecting water level data. Screw the data loggers cap on snugly and insta ll the protective housing on the stilling well assembly. Be sure to record the drop from the chosen benchmark to the water simultaneously with some of the readings taken after the gauge is calibrated and known to be taking accurate readings. T hat information will later be used in adjusting the data loggers water level r eadings to a tidal datum (such as mean lower low water). Download Data Files Each tide station data logger should be downloaded at least weekly, preferably more often, in order to ensure data are not lost due to wrappi ng, which occurs when the loggers memory is full and each new record causes deletion of the oldest record in storage. Al so, frequent visits to a tide station will reveal problems (malfunctions, stilling well movement, theft, vandalism, etc.) before many days of soundings are taken that can not be corrected for tides. Connect the HP48GX to the data logger as described above. From the Datalogger Start Menu, choose a data dump mode. Dump Since Set, which downloads all data collected since the logger was last set, is the usual choice. (An Entire Memory Dump downloads all dat a in the logger. If there is any doubt about whether data have been downloaded a nd backed up, the Entire Memory Dump will collect all possible readings Then the station-unique ID number will allow sorting out which records came from which site.) When a mode is selected and OK pressed, the data will be transferr ed from the logger to the HP48GX. Examining a plot of the data allows a quick data quality check. From the Datalogger Start Menu, select View Plots, and then scroll to select a file to view. The newest file will be at t he top of the list. If t he data are good, the plot will clearly show the rise and fall of the ti de. The small screen shows a limited subset (page) of the data at a time Pressing the Cancel soft key will display the next pages until the file has been completely view ed. Press the (X,Y) soft key to show cursor coordinates, then move the cursor via the arrow keys to some data points
19 near the top and bottom of the plot. This a llows verifying the displayed tide range is reasonable. Units are inches. (If t he stilling well bottom aperture is partially blocked or the pressure relief hole is completely obstructed, the water level in the well may rise and fall with the tide, but with amplitude less than the actual tidal variation.) Press Cancel to exit View Plots and then Enter to return to the Datalogger Start Menu. When the data dump is complete, the logger will continue to collect depth readings. Transfer Files to a PC Back in the office, connect the HP48GX ca lculator to a serial port on a Windows computer, using the same HP serial c able used with the data loggers. Start the Infinities PC Transfer 95 98 NT program and select Handheld Retrieval Device. Choose the serial port to which the HP calculator is connected and then click Receive Files. Status bars show the progress of the dow nload. The HP48GX shuts itself off when it is fini shed sending all of its files. The downloaded files can be immediately ins pected in a text or word processor or opened as delimited text files in a sp readsheet, for graphing or preparation of files for tidal correction of soundings. Equipment Settings The following sections cover the principa l settings for project equipment. Before using any piece of equipment, carefully read its accompanying user/operational manual. GPS Parameter Settings The Trimble Pro XR, TSC1 data logger, and the MSK beacon receiver are used for the boat/mooring and sign censuses; t he Trimble DSM212H is used for the depth survey. Feature positional a ccuracy obtained during data collection depends on several factors including the number of satellites, multipath, distance between base station and the rover, Posi tional Dilution of Precision (PDOP), Signal-to-Noise Ratio (SNR), and satellite elevation (Trimble Navigation Ltd. 1995). These factors may be controlled or monitored via software and hardware settings. The following discussion descri bes parameter settings for field data collection during the waterway management project. A more detailed discussion of each parameter may be found in the Trimble manuals that accompany the GPS equipment (Trimble Navigati on Limited 1998a, 1998b, 1998c). The Asset Surveyor software on the TSC1 da ta logger is used to set critical and non-critical parameters for data collection (Trimble Navigation Limited 1998a). As fieldwork progresses all settings should be confirmed daily, as they have been known to occasionally reset to their default values. Parameter settings are accessed from the Configuration menu, which is one of eight selections found on the Asset Surveyor main menu. T he following paragraphs discuss appropriate settings for each relevant parameter, whic h are displayed in bold italics in the tables that accompany the discussion.
20 Logging options is the first group of c onfiguration parameters found under GPS Rover Options. LOGGING OPTIONS Logging intervals Point Feature:5s Line/area:6s Not in feature: None Velocity: None Minimum positions: 1 Carrier phase Carrier mode:Off Minimum time:10 mins Dynamics code: Land Logging intervals specify the elapsed time between GPS positions that are logged, or recorded, by the TSC1. Point features (boat, moorings, derelicts, or signs) are the only feature type colle cted during the boat/mooring and sign censuses. The Point Feature logging interval should be set to 5 seconds, rather than the default 1 second, to help the operat or avoid logging multiple positions. During fieldwork only one position shoul d be logged for each point feature; logging is paused after one position is re corded and, then, feat ure attributes are entered into the data logger. Since only one position is to be collected for each feature, Minimum positions should be set to a value of one. If more than one position is accidentally collected for a feature, then during the editing process (explained later), the first position s hould be retained and all others discarded. The Dynamics code should be left at the default land setting, which is the mode for operating in areas where obstacles (e.g., condominiums or trees) may obscure satellite signals and when data collection takes place at a relatively low boat speed. Once Logging options have been set, retu rn to the GPS Rover Options menu by pressing Escape. Position filters settings control the computation and application of GPS positions. POSITION FILTERS Position mode: Manual 3D Elevation mask: 15o SNR mask: 6.0 PDOP mask: 6.0 PDOP switch: 8.0 Apply real-time: Yes RTK mode: Off
21 The Position mode is a critical setting, since it affects the operation of the Trimble Pro XR GPS receiver. This parameter should be set to Manual 3D, which assures that the receiver uses four or more satellites to compute positions. This setting usually will yield the most accura te GPS positions and allows for greater flexibility during fieldwork. The Elevation mask is set so that only satellites that are 15 degrees above the horizon are used to calculate positions. This is to assure that the same satellites us ed by the U.S. Coast Guard (USCG) radiobeacon6 station are those used during fieldw ork. Also, this setting helps to avoid the greater ionospheric noise that is associated wit h low horizon satellites. The Signal-to-Noise Ratio ( SNR) mask compares the information content and the noise7 that are carried by a satellite signal Increasing values indicate that the signal carries a relatively greater amount of information than noise; a value of 6.0 is the appropriate SNR setting. PDOP mask determines the maximum Positional Dilution of Precision allow ed to compute GPS positions PDOP is a measure of the quality of the spatial a rrangement of the constellati on of satellites that have been acquired by the DGPS receiver. The accuracy of GPS positions increases as the PDOP value decreases. A PDOP of 6.0 provides for sub-meter accuracy when using a Trimble Pro XR receiver. Use the Pathfinder Office Quick Plan utility to determine when acceptable PDOP will be available during a particular survey day (see Mission Planning). The Apply Real-time switch should be set to yes, since all GPS positions are to be corrected using the RTCM signal. The next parameters to c heck are the Communication s options located under the Configuration menu. REAL-TIME INPUT OPTIONS Radio type: Custom Baud rate: 9600 Data bits: 8 Stop bits: 1 Parity: None RTCM options Station:Any Age limit:20s 6 The U.S. Coast Guard established a network of radio-broadcast DGPS stations that cover the Pacific, Atlantic and Gulf coastlines of the U. S. plus some inland waterways. These sites broadcast RTCM-104 v. 2 format corrections utilizing Minimum Shift Keying (MSK) modulation of existing radio beacon signals. Each station ha s a broadcast range of generally 100 to 150 miles and their data can be utilized by any MSK beacon receiver, such as the Trimble Pro XR receiver, which has a with built-in MSK receiver. Real-time DGPS correction accuracy is specified by the Coast Guard to be better than 10 meters. Actual field accuracies have been found to be as good as 1 meter with a system such as Trimble's Pro XR. 7 Choose a location for the antenna with a minimal amount of ambient noise. Some common sources of electrical and magnetic noise are gasoline engines, television and PC monitors, alternators and generators, electric motors propeller shafts, equipment with DC-to-AC converters, florescent lights, power lines, and switching power supplies.
22 Real-time corrections are obtained from the radiobeacon component of the Pro XR and, thus, the parameters should be le ft as listed in the table above. The RTCM Station option is set to Any, which allows the receiver to acquire the best signal from available USCG radiobroadcast DGPS stations. USCG DGPS stations in Florida are located at Cape Canaveral, Key West, MacDill Air Force Base (Tampa), and Miami. The operational parameters and current status of all USCG radio-broadcast DGPS stations can be obtained at the following web site: http://www.navcen.uscg.gov/ADO/DgpsSelectStatus.asp Since the Pro XR integrated DGPS is us ed to apply real-time corrections, press the F1 soft-key on the TSCI keypad in or der to check the parameter settings. INTEGRATED DGPS Source: Beacon Mode: Auto range Frequency: N/A The Source for real-time position corrections is RTCM messages broadcast from one of the USGS MSK radiobea con stations listed above. Mode is set to Auto range, which allows the Pro XR to tra ck available stations and select the best one in terms of proximity and signal strength. Frequency is not applicable since the Pro XR is set to switch between available stations. Return to the Configuration menu by pressing the Escape key. The settings under Coordinate system and Units and display can be left at their default values as listed in the TSC1 Asset Su rveyor Software User Guide (Trimble Navigation Ltd. 1998a). The Time and date settings are for TSC1 display and file naming purposes only. GPS data is recorded in GPS time, which is essentially the same as Universal Time Code (UTC). Thus, t here will be no effect on GPS data records if you reconfigure the receiver and/or data logger when there is a change in the local time. Next, from the Config uration menu, select External sensors and highlight the selection for Laser and press the setup soft key. LASER RANGEFINDER Type: Atlanta Advantage Auto connect: Yes Serial port: Top The laser Type should be set to Atlanta Advantage and Auto connect set to Yes, since the range finder is used throughout both censuses. The rangefinder is connected to the top Serial port on the TSC1.
23 The last available selecti on from the Configuration menu, Hardware (TSC1), contains useful information and settings. HARDWARE (TSC1) LCD contrast: 30% Backlight: Off Auto shutoff: 20 Beep volume: High Free space: 1648kB PC card free space: N/A Battery source: External Internal battery: 100% External battery: Unknown Software version: 4.01 Lighting conditions change throughout the day and LCD contrast allows the TSC1 display screen to be adjusted accordingly. In general, with brighter lighting a higher value is required. It is best to leave the Backlight Off, as it places a relatively large drain on battery power. Auto shutoff powers down the TSC1 when no key has been pressed during the allotted time. Choose a setting between 1 to 60 minutes that best meets th e data entry habits of field personnel. Beep volume set to High will alert the user when certain data logger functions have been performed (e.g., position recorded). The remaining fields cannot be set, but offer important information to the user. Free space indicates how much TSC1 storage space is left for data (rover) files. Battery source indicates whether the TSC1 is running on its own in ternal batteries or from an external power source, such as the GPS receiver battery. Internal battery indicates the level of charge remaining in the TSC1s main internal batteries. When the TSC1 is hooked up to an external source the External battery field shows the power level, if available. The Software version of the Asset Surveyor software is also displayed. This concludes the discussion of settings for the Trimble Pro XR GPS. The Trimble DSM212H and it s integrated dual-channel MSK beacon receiver are configured using Trimble St andard Interface Protocol (TSIP) TALKER software installed on a PC (e.g., the AMREL laptop, which is used during the depth survey). The TSIP TALKER software is used to configure key GPS operating parameters: DGPS input and output, and NMEA-0183 output messages; as well as to monitor the current status of receiver processes. The DSM212H is connected to a PC serial port via Port B on the DGPS. The communication parameters are set using the TSIP TALKER software. Once communication is established between the TSIP TALKER software and the DSM212H, DGPS receiver par ameters are accessed from the drop-down menu.
24 The settings are the same as for the Trimble Pro XR. The Elevation Mask is set to 15 degrees, PDOP Mask to 6.0, Dynamics Code to land, and the Positioning Mode to Manual 3D. The Positioning Rate which is set to 1 Hertz (Hz), determines the rate at which the DS M212H outputs position reports to the HYPACK hydrographic software. The DGPS menu includes options fo r configuring the DGPS source and radiobeacon data acquisition channels, viewing radiobeacon information, and monitoring the health status of radiobe acons. The first set of parameters is located under Source. Radio-broadcast USCG DGPS stations serve as the DGPS Source for position corrections. Beacon Mode is set to automatic, which allows the receiver to acquire the best signal from available USCG DGPS stations. Two settings are available for beacon mode: auto range or auto power. Generally, auto range provides a more accurate position, as the receiver uses the signal from the closest station. When beacon mode is set to auto power, the strongest signal is used, which provides greater signal reliability. The Satellite Settings are irrelevant, as satellites are not used fo r DGPS corrections during the bathymetric survey.
25 The next set of parameters located under the DGPS menu Config uration set the DGPS acquisition mode, the maximum pseudorange correction (PRC) age, and the source of DGPS corrections. DGPS Mode determines receiver behavior when DGPS corrections are received from a radiobeacon station. Set the mode to On to assure that the receiver computes positions only when DGPS corrections are available. Set Max PRC Age to 20 seconds to eliminate older PRCs from position calculations, since they quickly age and lose accuracy. Set the External DGPS Source to Any Station to automatically acquire DGPS corrections from any radiobeacon in the area. The Beacon List and Beacon Health se lections availabl e from the DGPS menu provide information on the available radiobeacon stations including their status. The View menu lets you disp lay windows containing status information
26 collected from the receiver. These are usef ul for viewing receiver configuration and monitoring receiver processes during the bathymetric survey. Depth Sounders Bathy-500MFthe Bathy-500MF echo sounder is controlled using the 16 keys that are located on the front panel (Figure 4). The settings described below are those that have been found appr opriate during a hydrographic survey conducted for the WCIND along the Caloosa hatchee River and adjoining canals and waterways. The settings for other locati ons may be different. Only digital depth output has been used during WCIND surveys; not the paper char t capabilities of the sounder. Refer to the user manual fo r a complete description of Bathy-500MF functions and parameter settings (Coas tal Oceanographics, Inc. n.d.). RANGE DEPTH DATA GAIN SV GATE CHART MARK ALARM PWR OFFSET COM FEET MTRS ENTER Figure 4. Bathy-500MF echo sounder front panel. To power up the Bathy-500MF, simultaneously depress the PWR and ENTER keys. During the startup, view the LCD disp lay to determine if the unit is set to the proper transducer frequency (currently using a 200 kHz transducer). If the transducer frequency is not proper ly set, then quickly press the COM key and select the proper transducer frequency (e .g. 200 kHz) from the SET FREQ menu. The RANGE setting will depend on the range of depths encountered during a particular survey. A setting of either 0 ft (or 0 ft) is normal for surveys conducted for the WCIND. The PHASE setting is 0 ft, the GAIN is set to Auto, and TVG set to 100. The daily bar check is used to determine if any
27 corrections are needed due to variations in sound velocity. If there is a difference between the sounder depth reading and t he bar depth, sound velocity ( SV) is adjusted until the two depths match. Fi eld notes should be kept to record observations from each daily bar check and any adjustments to SV that are made. The data output I/O format for transmitting depths to the HYPACK software is selected by repeatedly depressing the COM key. The NMEA dbs output format is recommended. The depth of the transducer bel ow the waterline is determined under normal load conditions and the measurement is entered into the Bathy-500MF using the OFFSET key. ALARM s can be set to notify the operator when sounder readings are above or below specified limits. Alarms can be useful to notify the operator when the sounder gives false readings. Potential causes of false readings can include tur bulence, temperature gradients, density variations, and biological layers. Horizon DS150the procedures for entering settings into the Horizon echo sounder are described in the user m anual (Standard Communications 2001). The keel offset (depth of the transducer below the waterline) is determined under normal load conditions (equipment and personnel) and the measurement is entered into the HYPACK Hardware driver settings for the Horizon. The setting for Display Damping is to control for rough water conditions, schools of fish, and thermal layers, all of whic h can cause erratic depth readings. Display damping controls the rate that the displayed depth can change and will help remove these variations. There are three levels of damping, with d1 having the least effect and d3 having the greatest ef fect. When operating in shallow or at high speeds it is best to use a low leve l of damping. During past WCIND surveys, the Horizon DS150 setting for damping was set to D1. The Turbulence Setting provides three settings of turbulence rejection: t1, t2, and t3. A setting of t2 should be used unles s a problem occurs while underway. A setting of t1 enables the instrument to wo rk in water as shallow as 3 feet at an increased susceptibility to water turbul ence and surface noise. A setting of t3 provides maximum immunity to wate r turbulence and surface noise at the expense of shallow water (l ess than 4 feet) performance. Mission Planning The boat/mooring and sign censuses and t he depth survey require the use of DGPS to log features. Thus, mission planning is critical to project efficiency. To ensure adequate positional accuracy, the constellation of satellites must be satisfactory. Enough satellites must be visibl e, they must be spread over a large area of the sky, and they must be su fficiently high above the horizon. These factors all contribute to accuracy or lack thereof. Combined, they result in a number called Positional Dilu tion of Precision, or PDOP. There is no point in trying to collect data when the PDOP is too high, as the TSC1 is set to not collect data when PDOP exceeds 6. When this occurs, a PDOP too high message appears, and the data logger will not record a position. Wi th a PDOP limit of 6,
28 field personnel can work most of the time. The TSCI also is configured to require four or more satellites and an elevation mask of 15o in order to compute positions. To work efficiently, it is best to use the Pathfinder Office Quick Plan utility (Utilities Quick Plan) to forecast po ssible downtimes. But first, it is necessary to tell Pathfinder Office where the satellites will be in the future. This is done by downloading an almanac file from the TSC1. A new almanac should be downloaded from the data logger every mo nth or so. (The TSC1 records the latest almanac whenever it is used.) It is just another data f ile to be downloaded from the data logger, using the same pr ocedure as for rover files. Select Almanac as the Data Type rather than Data Quick Plan will automatically reference the latest almanac file if you always save new ones to the same directory. Start a Quick Plan session. If necessary define a location. (Dont forget our longitude is West; the default is East). Select a day of interest. Look at the PDOP graph to see how it varies throughout eac h day. If below 6 all day, data may be collected any time. If there are times w hen PDOP exceeds 6, it may be possible to plan lunch, refueling, or some other activity for those periods. Field Censuses and Survey Data Dictionaries The boat and mooring8 census, the sign census, and the depth survey are accomplished using data dictionaries created in Pathfinder Office and uploaded to the TSC1 data logger. Copies of t he most recent data dictionaries and a printout (PDF) of each are contained on the CD-ROM that accompanies this manual (/FieldProcedures/Data Dictionary). Sometimes it is necessary to modify a data dictionary to reflect changing circum stances that may arise during a new project (e.g., a new mooring type). Modifications are accomplished with the Data Dictionary Editor in Pathfinder Office (Utilities Data Dictionary Editor) and then uploaded to the Trimble data logger using the Data Transfer utility (Utilities Data Transfer). Boat and Mooring Census The purpose of the boat/mooring census is to determine the location and characteristics of all boats and moorings within the study area. This census is conducted during the peak boating season December through Aprilusing the Trimble Pro XR, the TSC1 data logger, and the Laser Atlanta Advantage laser rangefinder. The data logger must contain the boat/mooring data dictionary (Boat2001.ddf), which has two point features: one for boats/moorings 8 Moorings are defined as boat locations that are either occupied or vacant. Mooring types include anchorage, beached or blocked, boat lift, davits, dry stack, float/ramp (usually for personal watercraft), hoist, mooring, ramp, seawall, trailer, and wet slip.
29 (BOATMOOR) and the other for derelict vessels (DERELICT). The BOATMOOR characteristics (fields) colle cted during the census are: 1) BEGINwhether the feat ure is a boat (and its a ssociate mooring) or an empty mooring. 2) FACILITYland use classification to which the boat and mooring are associated. 3) BOAT TYPEuse char acteristic of the boat. 4) MOORINGmanner in which the boat is secured. 5) LARGOlength class to which the boat belongs (feet). 6) AGEdecade in which t he boat was manufactured. 7) MAKE/MODELmanufacturer ma ke and model of the vessel. 8) VARIABLE DRAFTwhether the boat has variable draft capabilities. 9) DRAFTboat draft to the nearest foot. 10) AERIALcorresponding aeria l photo identification number. 11) STATE REGbow number; used if field identification not possible. 12) VINmanufacturer hu ll identification number; should be on transom; used if field identification not possible. 13) PHOTOphotograph associated wit h feature; used if field identification not possible. 14) COMMENTuser notes. 15) DATEdate when the boat was su rveyed; automatically generated. 16) TIMEtime when the boat was surveyed; automatically generated. A spreadsheet of reference numbers t hat correspond to boat manufacturer makes and models is maintained for the boat census. During the census, a printout of the spreadsheet table, sort ed by make/model, is used to enter a reference number into the MAKE/MO DEL field for each logged vessel. Make/models that are encountered during the census, but not found on the printout, are added to the table printout and assigned the next available reference number (numbers ascend numer ically). At the next available opportunity, the spreadsheet is updated with the new make/models and their corresponding reference numbers and re-sor ted by make/model. A copy of the most recent make/model tabl e is contained on the CD-ROM (/FieldProcedures/MakeModel.xls). Most important for waterway management system analyses is determination of vessel draft. If identification of boat ma ke/model and other data do not reveal the draft, the field personnel should take other measures, includ ing asking the boat owner or a knowl edgeable neighbor. The DERELICT point feature in the boat/m ooring data dictionary contains all of the above fields (except BEGIN) and, in addition, the following: 1) FMPMarkwhether the vessel has a Florida Marine Patrol (FMP) mark.
30 2) DCONDderelict condition. 3) DBEACHwhether the derelict is beached. 4) DAFLOATindicates if the derelict is afloat. 5) DSUBMERGEsubmersion perc ent of the derelict vessel. The data fields for boat/mooring and derelict features are further described in the sample metadata files contained on the CD-ROM (/FieldProcedures/Metadata/boat s.htm and derelicts.htm). The boat/mooring census is conducted for all boats (whether they are located in the water or on land) and moorings on salt-water accessible canals and waterways. Facilities that are survey ed may be commercial, governmental, or residential. Examples include single and multi-family residences, anchorages, clubs, dry stacks, hotels/motels, marinas restaurants, shops, and boat yards. Dealer inventory stock at commercial facilities, such as boat yards and marinas, is not included in the boat census. The TSC1 data logger is set to log DGPS positions at a five-second interval and only one position is logged for each feature. Position logging is paused after the first position is recorded, feature charac teristics are recorded, and the feature then is saved. In addition to using DGPS equipment to log boat, mooring, and derelict vessel information, each feature should be marked on large-scale (1:2400 to 1:12,000) orthophoto maps, or aerials, as the survey progresses. The location of some features may need to be adjusted during the post-survey editing process, at which time the field annot ated photomaps will prove invaluable. Onemeter USGS DOQQs normally are used to produce the photom aps; however, the availability of higher resolution imagery from city or county sources should be ascertained. If possible, parcel boundary (lines) should be added to the photomaps to guide placement of feature marks. Each feature mark should be color-coded according to feature type: e.g., boat (red) or mooring (blue). At the end of each field day a number of tasks should be completed. First, all rovers collected using the TSC1 data logger should be downloaded onto a computer using the Pathfinder Offi ce data transfer utility (Utility Data Transfer). Once downloaded, the rovers should be viewed in Pathfinder Office, over background imagery, to insure that the data is in t he correct geographic location, covers all areas that were to be to be surveyed that day, and that no data gaps exist. Backup copies of original and edited rover files should be maintained on separate media in a secure location. If possible, copies should be sent electronically to personnel located at another site. Boat/mooring census data should be cleaned and edited as soon after field collection as possible, since the recollec tion of field personnel diminishes with time. Preferably, editing sessions will occur at least weekly. The first editing step is to check the data using the SSF Reco rd Editor, which can be accessed from Pathfinder Office (Utilities Other SSF Record Editor). Each feature (boat,
31 mooring, or derelict vessel) is checked to assure that only one position was recorded by the DGPS. The survey vessel usually is in motion during the census and the average of multiple positions results in a less accurate location determination for each feature. Therefore, only the first position is maintained if multiple positions have been recorded. The following technique greatly facilitates this editing process: Once the rover is loaded into the SSF reco rd editor, select View Records by Type. Click Hide All. Then turn on (check) Feature Block Start FON, Featur e Block Off FOF, and Position Records POS. This hides everything except for the start and end of each features records and one line for each position logged. It is then easy to spot multiple positions for a feature and to delete all but the first one. Be sure to Save after completing the edits. Note: Re cords deleted are not removed from the rover file, but are simply flagged to be disregarded. They may be undeleted at any time. Upon completion of the boat/mooring cens us the data needs to be cleaned and edited. These procedures are best accomplished within a data base manager, such as Microsoft Access. This involves summarizing each attribute by unique value and checking for correct spelling and logical consistency. Some examples include checking boat draft versus boat length or make/model; and checking the facility value obtained from t he field census versus that contained in the property appraiser database. Signage Census The purpose of the signage census is to determine the location and characteristics of all boat-related signs wit hin the study area. This census is best conducted before the depth survey, so that a set of aerials containing sign locations and characteristics can be produced to guide the depth survey. The signage census is carried out using the Trimble Pro XR DGPS, TSC1 data logger, and the laser rangefinder. The data logger must contain the signage data dictionary (Sign2000.ddf), which has two point features: one for signs (SIGN) and the other for hazards (HAZARD). The sign characteristics (fields) collected during the census are: 1) SITEwhere the sign is located (e.g., bridge). 2) TYPEstructural characteristic of the sign (e.g., buoy). 3) MESSAGEmessage that the sign c onveys (used in conjunction with the comment field; e.g., channel mark). 4) LABELcategorization of the sign into 6 general classes. 5) STATUSstatus of the sign (e .g., permitted or non-permitted). 6) CONDITIONphysical condition of sign. 7) COMMENTobservation of field per sonnel (use in conjunction with message field). 8) DATEdate on which the field obs ervation was made; automatically generated.
32 9) TIMEtime at which the field observation was made; automatically generated. The hazard (HAZARD) point feature, while not included in the waterway management scope of work, was created to map existing navigation hazards, such as submerged pilings or branches The hazard characteristics collected during the census are COMMENT, DATE, and TIME. The sign fields are further described in the sample signage met adata file contained on the CD-ROM (/Metadata/signs.htm). The same daily and weekly editing procedures followed during the boat/mooring census should be observed during the sign census. Depth Survey The purpose of the depth survey is to obtain channel centerli ne soundings for all salt-water accessible canals and waterways within the study area. The timing of the depth survey is not as critical as that of the boat/mooring census. The depth survey is carried out using the DSM212H DGPS, AMREL laptop, and the Bathy500MF and Horizon DS150 echo sounders. Survey Procedures Prior to conducting the depth survey, tide gauges should be installed and checked to make sure they are work ing properly. Ther e are a number of corrections that need to be applied to t he raw soundings to account for error sources attributable to syst ematic and system-specific in strument errors, static and dynamic variations in boat draft, environmental conditions, and tidal variations (National Ocean Service 1999; U.S. Army Corps of Engineers 2001). Instrument Error and Sound Velocity Corrections to determine corrections for sound velocity and instrument error, bar checks are performed within the survey area. A minimum of two bar checks is conduc ted during each survey day to verify the depth reading from the Bath y-500MF and DS150 transducers. Bar checks should take place at the start and end of each survey day. The bar consists of a metal plate that is lower ed to set distances, at 5-foot intervals, below each transducer. The sounder depth r eading, at each 5-foot interval, is compared to the bar depth and, if necessa ry, the appropriate correction factor is entered into the DS150 instrument as one component of the keel offset, along with the static draft correction (see below ). To apply the corre ction to the Bathy500MF, the velocity setting is adjust ed until the depth readi ng equals the bar depth. If more than one correction factor results for either sounder, the corrections are cataloged and applied to the soundings during post-processing. At the end of each day, the two daily bar checks are compared and if they agree by 0.3 feet or less the surv ey data are accepted. Otherwis e, the data are rejected and the area resurveyed. Daily bar checks are recorded in a field notebook.
33 Static draft corrections the static draft correction a ccounts for the depth of the transducer face below the wa terline. The measurement is made at least to the nearest 0.1-foot as determined under norma l load conditions with boat personnel in their survey positions. A person standing on a dock next to the survey vessel is best situated to make the measurement. The correction is entered into the Bathy500MF as a component of the offset, along with any necessary sound velocity correction (see Instrument Error and Sound Velocity Corrections). The correction is entered into the DS150 as a Keel Offset. Squat and Settlement differential leveling c onducted, under normal load conditions (including personnel, fuel, and equipment) determines squat/settlement corrections to the near est 0.1-foot for the range of survey operating speeds. The range of operati ng speeds may be determined from a survey of posted speed limit s within the study area. Squat/settlement corrections should be determined in non-tidal waters, under calm conditions, in depths that equal the average expected for the study area. To determine squat/settlement corrections a level is set-up on a dock and the boat run parallel to the shoreline in front of the level, at various speeds. A rod is held over the transducer and a series of obs ervations taken with the vessel standing still, and at the range of survey oper ating speeds. The squat/settlement correction factor for each operating speed should be based on the average of a minimum of three runs at each speed. Squat/settlement corrections are automatically applied during the depth survey by installing the Draft Table Driver within the HYPACK hydrographic survey softw are. The Draft Table is a listing of correction values with their corres ponding vessel speeds. The average boat velocity, as determined from the DGPS, is recorded for each RPM level. Motion Corrections for depth surveys conducted in protected, near shore waters under calm sea conditions, correction for heave, the only motion correction applicable for a single-beam su rvey (National Ocean Service 1999), is considered unnecessary. During bathymetry data collection in the residential canal systems, the primary w eather considerations are crew safety (especially with regards to lightning), collision avoidance (when maneuvering near other vessels in heavy sustained or gusty winds), and efficient operation of instrumentation (particularly in heavy rain). On workdays when conditions are suitable in those regards, the weather does not significantly affect boat dynamics in the canals, and data quality remains high. The crew should plan to work only sheltered waters, such as canal systems, on windy days that are otherwise safe for operations. HYPACK Software Settings There are a number of HYPACK software settings that are necessary to conduct the depth survey. Detailed information on these settings is contained in the HYPACK user manual (Coastal Oceanographics, Inc. n.d.).
34 The GEODETIC PARAMETERS settings depend on the projection parameters and the coordinate system of the backgr ound imagery used for a project. If USGS DOQQs in Albers Equal Area projection are used, then the parameters are set as shown in Table 3 and represented in Figure 5. Table 3. H YPACK geodetic parameters. Geodetic Parameters Predefined Grids none Distance unit Meter Depth unit same as horizontal Ellipsoid WGS-84 Orthometric Hei ght Correction 0.00 Projection Albers Equal Area Central Meridian 84o 00 00.0000W Reference Latitude 24o 00 00.0000N North Parallel 31o 30 00.0000N South Parallel 24o 00 00.0000N False Easting (X) 400000.0000 False Northing (Y) 0.0000 Hardware Setup Four device drivers need to be install ed for the depth survey equipment to communicate properly with the HYPACK software. These include the two echo sounders: the Bathy-500MF and the DS150; and the DSM212H DGPS. A fourth device consists of a table to quanti fy the relationship between boat speed and squat/settlement. The table is used to apply real-time squat/settlement corrections to raw depth s during the survey. The relative location of each sensor that provides input to the HYPACK software must be determined. Select a point on t he survey boat to serve as the boat origin. Each sensor is then referenced bas ed on its location relative to the origin: to starboard(X-direction) and forward (Y -direction). The offset units must be the same as those used to re cord depths (e.g., meters). Figure 6 illustrates the Key West survey vessel as configured during the Lee County Phase 3 depth survey, with tw o echo sounders and one DGPS antenna. The boat origin was positioned directly over the Bathy-500MF transducer, above which was mounted the DGPS antenna. All offsets forw ard and starboard of the
35 Figure 5. HY PACK geodetic parameters. boat origin have a positive value. The DS 150 Horizon transducer was located aft of (negative offset) and to the port ( negative offset) of the boat origin. Once the preliminary tasks are completed, in itiate the device driver installation process by following the HYPACK manual instructions that pertain to Hardware Setup. The specific settings for each survey device are detailed below. Bathy-500MF: From the Select devic e type dialog choose the NMEA-0183 driver (NMEA.dll) and give the device an appropriate Name such as BathyNMEA. The Update frequency controls the rate (ms) at which HYPACK requests a depth reading from the echo sounder. This value will depend on the speed of the survey vessel. To contro l data density during Phase 3 of the Lee County project, which took place at no wake speeds, the setting was set to 500 ms. The device Type is Echosounder and the selected Options should be Record raw data and Record quality data. Depress the Record button and activate the Always option; Depress the Connect button and set the port (usually serial) and the port parameters: Baud rate -9600, Parity -none, Data bits -8, Stop bits -1, and Flow control -None. Depress the Offsets button and enter starboard and forward offsets as necessary. Depress the Setup button and select the following NMEA sentences: DBS, DPT, and DBT and the sentence output as GLL.
36 DS150 Horizon: From the Select devic e type dialog choose the NMEA-0183 driver (NMEA.dll) and give the device an appropriate Name such as Horizon. The Update frequency controls the rate (ms) at which HYPACK requests a depth reading from the echo sounder. The horizon outputs depths at a slower rate than does the Bathy-500MF; this setting can be left at 50 ms. Device Type is Echosounder and the selected Options should be Record raw data and Record quality data. Depress the Record button and activate the Always option; Depress the Connect button and set the port (usually serial) and the port parameters: Baud rate -4800, Parity -none, Data bits -8, Stop bits -1, and Flow control -None. Depress the Offsets button and enter the st arboard, forward, and height offsets as previously determined. Depress the Setup button and select the following NMEA sentences: DPT and DBT, and set the sentence output to GLL. DSM212H: From the Select device type dialog c hoose the NMEA-0183 driver (NMEA.dll) and give the device an appropriate Name such as DSM212H. Leave the Update frequency at 50 ms. Device Type is Position, Heading, and Speed and the selected Options should be Record raw data and Record quality data. Depress the Record button and activate the Always option; Depress the Connect button and set the port (usually serial) and the port parameters: Baud rate-9600, Parity -none, Data bits -8, Stop bits -1, and Flow control -None. Depress the Offsets button and enter the latency, which was determined in consultation with Coastal Oceanographics, Inc. to be -0.3 for the DSM212H; enter starboard and forward offsets if necessary. Depress the Setup button and select the following NMEA sentences: GGA and VTG, select the options: send alarm when non-different ial and suspend logging when nondifferential. Set the HDOP limit to 2. 50 and choose the option to generate a GLL NMEA sentence. Squat/Settlement Corrections: From the Select device type dialog choose the Coastal Oceanographics Draft Table driver (DraftTable.dll) and give the device an appropriate Name such as KWSquatSettlement. Leave the Update frequency at 50 ms. Device Type is Draft and the selected Options should be Record raw data and Record quality data. Depress the Record button and activate the Always option; Depress the Connect button and set the port (usually serial) and the port parameters: Baud rate-9600, Parity -none, Data bits -8, Stop bits -1, and Flow control -None. There are no Offsets. Depress the Setup button enter the speed (knots) and squa t/settlement relationships in the table, as determined during the squat/s ettlement calibration tests described previously. Remember that the units need to be the same as those set for depth when entering the Geodetic Parameters (meters, for the Albers projection).
37 X-Axis (Positive Starboard) Y-Axis (Positive Forward) Bathy 500 Transducer (No X or Y Offset) GPS Antenna Horizon X Offset (neg.) Horizon Transducer Horizon Y Offset (neg.) Figure 6. Determi ning depth sensor offsets. In the HYPACK Max Matrix Editor (Preparation Editors Matrix Editor) construct a matrix file for the study area. As soundings are collected, the Survey program will fill in the matrix cells with pre-selected sounding colors, allowing continual monito ring of data goodness and enabli ng the crew to see a track generated over the background imagery as the boat moves. It is preferable to make one large matrix for each work area. This need be done only once for each area, as Survey retains the matrix file in the project. A cell size of 3 meters gives good results. After performing the initial bar check for each sounder, begin the survey. The boat should follow a planned course, to sound centerlines and each side of
38 waterways. Three parallel lines are su rveyed at 25, 50, and 75 percent of the canal width. The data collector monitors progress and directs the boat operator as required. The boat should stop when soundings are missed due to absence of DGPS positions or other causes. Audible and visible alarms alert the crew to data dropouts. The data collector should pause logging when the boat stops or maneuvers off the planned course to avoid traffic or other hazards. Separate windows provide continuous, real-tim e monitoring of Sounder and GPS data streams. When the water is too shallow for sounder operation, the data collector or boat operator should man the staff gauge. M anual soundings should be noted on the aerial photomap, along with the date and time. If soundings cannot be logged automatically due to excessive PDOP or loss of the beacon under bridges, near large buildings, etc., record sounder readings on the map, again with the date and time. At the end of the day, conduc t the second bar check and return the boat to its berth. With the AMREL PC back in the offi ce, back up the days raw files to other media, such as Zip disks, either by simp ly copying the files in Windows Explorer or by compressing the HYPACK project onto the backup media (File Compress Project). Be sure to DESELECT background image files when compressing the project!
39Post-processing of Survey Data Tide Corrections A specialized computer program, Survey Tide Correction (SURVCORR.exe), created by the University of Flori da Coastal and Oceanographic Engineering Program, corrects soundings for the local state of the tides at the time each depth was recorded. The complete SURVCORR operators manual, found in the Appendix, details the func tionality of the program and specifies the required content and formatting for each input f ile. The SURVCORR program is found on the CD-ROM. Each SURVCORR session requires three ASCII-text-formatted input files: (1) uncorrected soundings (Survey Data File ); (2) a baseline of georeferenced points, along which time and tide inte rpolation algorithm s operate (Baseline Location File ); and (3) tide gauge readings with interpolated time and location tags (Baseline Tide Data File ). The program can correct soundings taken near a single tide gauge in the one-gauge case (with interpolation based only on time) or between pairs of gauges in the two -gauge case (interpolating over both time and distance). SURVCORR output is a text file cont aining the raw depth, corrected depth, date/time, and XY coordinates for each sounding. This file can be used to generate an ArcView event t heme and/or ArcInfo coverage of corrected depths. Note: The two required header rows for eac h SURVCORR input file are not used in calculations and may be left blank; they are available to make the files self documenting. Figure 7 is a diagram of data flow from the tide gauge and sounder outputs through generation of tide-corrected ArcView GIS shapefiles. Survey Data File The following steps for generating the Survey Data File result in a sounding distribution that is useful for data display, map atlas printing, and channel construction for restriction analyses. T hese steps apply to files from one depth sounder. 1. Open each raw file for one sounder in the HYPACK Single Beam Editor, then save into a catalog in the Edited Data Files folder. (Do not use presorting to thin the data.) 2. With the HYPACK Sort utility (Processing Sounding Selection Sort), sort (thin) all the soundings from the desired sounder for an area, selecting an appropriate radius, such as 6 meters. (The utility can sort an entire catalog of edited files at once.) Save the out put XYZ file with an appropriate name, then change the file name extension to .txt. Open this file in a word processor,
40 Figure 7. Flow diagram of tide correction procedures.
41 replace the space delimiters with commas and add headers: X, Y, and Corr Depth. 3. With the HYPACK User Defi ned Output utility (Utilities File Work User Defined Output), export the full set of soundings, with desired attributes (including, at least, X, Y, Raw Depth1, Corr Depth1, date, and time). Be sure to select a comma-delimited output format. Append the extension .txt onto the file name. In a word processor, add headers for the attributes, separated by commas. (This file may be 25MB or larger, but MS Word will be able open it for editing; WordPad may not suffice, and NotePad almost certainly will not.) 4. Import the two new .txt files into ArcView. 5. In a View, use View Add Event Theme to creat e a new theme from the XYZ table. The table still can not be edi ted (not being a .dbf file), so use Theme Convert to Shapefile. Once the data are in a shapefile, the table will be editable. 6. Create two new numeric fields (XPlus and YPlus). The default field width of 16 characters is satisfactory. Calc ulate XPlus = X*100 and YPlus = Y*100. (ArcView rounds floating-point numbers to integers when converting them to strings. However, it is necessary to retain two decimal places in the XY coordinates to avoid ambiguity in the table join process, step 8, below. When ArcView rounds XPlus and YPlus to int egers, the significant digits are retained.) 7. Create a new string field called Join XY. Make it wide, say 32 characters. Using the Field Calculator, calculate it equal to XPlus(asString) + YPlus(asString). 8. Similarly, make an event theme from the large table c ontaining the desired attributes and convert it to a s hapefile. Create and populate XPlus, YPlus, and JoinXY fields in this table, as described in step 6 and 7 above. 9. Join (Table:Join) the large attribut e shapefiles table to the sorted XYZ shapefiles table, using Join XY as the Join Item. The la rger attribute table is the source table, and the smaller XYZ table is the destination table. (ArcView Help explains the Join proc ess very well.) Now, each sounding in the sorted shapefiles table has the appropriate attributes (plus a lot of extra stuff) attached to it. Sani ty check a few records. 10. Important: Immediately convert the sort ed sounding shapefile, with its joined table attributes, to a new shapefile in order to preserve the join and make the table editable. Attempting to edit the newly-joined table, especially deleting fields, before converting to a new shapefile will cause ArcView-and often, Windows-to crash 11. Create a new string field (UT) in t he new shapefiles table, 24 characters wide. Populate it by adding the Date fi eld to the Time field with the Field
42 Calculator. Use the ++ operator, which will insert a space between date and time. 12. Delete surplus fields. For instance, there will be two X and two Y fields, the XPlus and YPlus fields, the JoinXY field, and an extra depth field, which are no longer needed. (Do not delete fiel ds that will be of subsequent use, such as Raw Depth1. Use Table Properties to hide, by unchecking, such fields. They will no longer be visible, and they will not be included when exporting the table as a text file. They will be again available when checked in Table Properties.) 13. Create a new numeric field called Depth_ft. Calculate it equal to Corr Depth 3.28083989501, to c onvert meters to feet. 14. Inspect and edit the shapefile. If all is OK, it is now safe to delete the XYZ and attribute text tables, to save disk space and unclutter the ArcView project. In a spreadsheet application, reformat the tabl e as required for the SURVCORR Survey Data File. Reformat the UT fiel d into the days-from-1900 numeric format and sort in chronological order There should be two header rows and four data columns, in the following order: time, X, Y, depth (i.e., UT, X, Y, Depth_ft). At this point, the Survey Data File is ready for inputting into SURVCORR. Baseline Location File In the two-gauge case, an auxiliary program, BASELINE2.exe, generates the Baseline Tide Data File for SURVCORR.exe. As BASELINE2.exe and SURVCORR.exe each require the Baseline Loca tion File for input, it is logical to create it next. (For the one-gauge case, the BASELIN E2 program is not used; the Baseline Tide Data File is generated by simply making a one-gauge data file and then adding a third column, identical to the second.) Make careful note of which is the starting and the ending tide gauge station. (In a given study area, baselines should be consistently constructed in the same directionfrom, say, north to south or eas t to westif possible. ) A simple way to construct this file is to create a new point theme in ArcV iew and mouse-click along the baseline over a background map, beginning at the starting gauge location and stopping at the ending gauge A baseline point should be added at each significant turn or intersection al ong the waterway. Either run the ArcView Avenue script addxycoo.ave or use the ArcView extension Addxycoord.avx (on the accompanying CD) to add attribute table columns for the XY coordinates of each point. Add a column of ID numbers (1, 2n). Then, export the attribute table as a text file, with columns in this order: ID, X, Y. In the one-gauge case, the Baseline Loc ation File has only two rows: ID numbers 1 and 2 populate the first column, and the same XY coordinates are used in both rows. The coordinates are not used for interpolation, so need not be identical with those of the gauge location.
43 Tide Gauge Data File To prepare the Tide Gauge Data File for BASELINE2, using data downloaded from Infinities tide data loggers (see Se tting the Tide Gauge Data Logger), it is necessary to (a) delete all header rows but two and (b) delete all data columns but the last two, which contain time (i n days from 1900) and water level (in inches of drop from the gauge transducer to the waters surface). If tide files from more than one dump from a data logger site are required, they should be concatenated into one file Convert the drop in negative inches to positive feet, and subtract from the elevation of t he gauge (in feet, relative to the chosen datum, usually local mean lower low water) to yield the water surface elevation relative to MLLW. The time column should be in the numeric days-from-1900 format. For the two-gauge case, combine files from two tide gauges into one, with a single time column followed by two water level columns. Be sure the first level column is from the first station on the baseline and t he second level column is from the file for the last station on the baseline. Veri fy that all records in both water level columns are in the correct rows for the ti mes they were recorded. Also, be certain the final data file is sorted by time before saving .) Run BASELINE2. The output is a new text file, the Baseline Tide Data File. It is correctly formatted for input into SURVCORR. SURVCORR Output File With the Survey Data File Baseline Location File and Baseline Tide Data File as inputs, run SURVCORR.exe to generate a file of soundings, relative to MLLW and corrected for tides. Caution: SURVCORR is into lerant of missing data, nonnumeric data, and times that are not sorted in chronological order. The program has few error messages; the usua l results of data errors are (1) the program stops and its window vanis hes or (2) output data are incorrect, not necessarily in obvious ways. If the time span of the tide data does not encompass the times at which soundings were taken, an appropriate error message will result; however, this message may also appear if input data are just incorrectly sorted by time. The program has no way of knowing if the start and end stations of a baseline are transposed. It is imperative to be careful and methodical in preparing data files for input into SURVCORR and then to inspect the output for reasonableness. In a spreadsheet, convert the days-from -1900 times to the desired date/time format. Delete the empty first column and one of the two header rows, leaving a row with the column headers Time, X, Y, Orig Depth, and Corr Depth. As the output file includes XY coordinates, a straigh tforward way to get it into a GIS file is to import it into an ArcView project as a table. Then use the table to add an event theme to a view (ViewAdd Event Theme). If an event themes attribute table is not a .dbf file, it can not be edited, so the new theme should immediately be converted into a shapefile (ThemeConvert to Shapefile), which can be
44 inspected and edited. For use in Regional Waterway Management System analyses, the ArcInfo SHA PEARC command will convert the shapefile to a coverage. Assigning Parcel Identification Numbers to Boats and Moorings Regional Waterway Management System gui delines require the association of each boat and mooring feature with the county Parcel Identification (PID) number of the parcel with which the feature is associated. Usin g the PID as a Join item, the name and address of the parcel owner can be attached to each feature. The county property appraiser office can supply GIS-format maps of parcels for the study area. These maps are very la rge files. Only parcels near waterways accessible by boats from saltwater are of interest to the proj ect; therefore, a preliminary step should be to delete all parcels more than approximately three away from such waterways. The time fo r this editing is quickly regained in the resulting speedup of computer processes, such as screen re-draws. It may be similarly helpful to divide a large study area into several small parcel maps. An efficient way to associate each boat and mooring with the appropriate PID is to use a freeware ArcView extension ca lled Nearest Features. (The data CD contains a copy of the extension.) No te: The versions of Nearest Features available from the ESRI Web site and other online sources do not accommodate numeric fields as wide as PID numbers. Be sure to use the version provided on the CD. Important: This PID assignment work should be done before separate boat and mooring themes are extrac ted from the boatmoor theme. Add an ID field (UFReference) to the boatmoor theme attribute table and populate it with a unique number for each feature. (This may be done easily by running the ArcView sample script addid.ave. Be sure the boatmoor theme attribute table is the active window before running the script.) Then, (a) PID assignments will have to be done only once, and (b) each occupied mooring will retain the same PID and UF-Reference number as its boat. After this point in the analysis process, do not change the existing UF-Reference numbers If features are added, simply assign them new UF-Reference numbers greater than the largest one already used. Nearest Features automatically finds features nearest to each other in two different ArcView themes. It offers a variety of ways to use and display parameters associated with t he feature pairs it identifie s, so many options are available when it runs. Most of these may be i gnored for our purposes. First, copy the file nearfeat.avx into your ArcView extensions directory (C:\ESRI\AV_GIS30\ARCVIEW\EXT32) and tu rn on the Nearest Features 3.4 extension in your project. A new button will appear above the view.
45 1. Nearest Features works on the assumption that each boat and mooring is closest to the correct parcel. Howeve r, parcel maps are not made with GPS accuracy and will likely require adjustment s. Examine the parcels in an area of interest (for instanc e, a residential canal syste m) for proper alignment with the base imagery. If boats and moorings are nearer incorrect parcels than correct ones, start editing the parcel theme (make it active and select Theme Start Editing), select the parcels in the area of interest, and slide them into place over the base map. (It is almost certainly best NOT to save the edits to the parcel theme at this time, and it is OK to leave the parcel theme in editable mode duri ng the subsequent steps.) 2. Make both the boatmoor and parcel themes active. Select their desired features, using the Select Feature tool; Shift-select to add features to those already selected. Remember, with two themes active (boatmoor and parcels), the Select Features tool simultaneously selects features of both themes. (If no features are selected, the Nearest Feat ure extension acts on all features of both themes.) 3. Click the Nearest Features button above the View. 4. For the Input theme, choose the boatmoor theme. For the ID field, choose UF-Reference. Click OK. 5. For the Comparison t heme, choose the parcel them e. For the ID field, choose PID. Click Add and then OK. 6. In the next dialog, make sure Num ber of Closest Comparison Features per Input Feature is set to 1. Also, ma ke sure the RESULTS Data Table for Nearest Features has Comparison Featur e ID checked. Make sure the Join Tables item is unchecked. (These are the defaults.) Click OK. 7. In the next dialog, highlight Nearness Number 1. Choose Connect Centroids under Line Connec tion. Choose a line style and color. Then click Add to List. Click OK. 8. In the next dialog, tell the program where to write the output data table and assign it a meaningful name. Click OK. 9. After the program runs examine the output table and the new lines in the view. If necessary, refer to the boatmoor and parcel theme tables and edit the output table for any cases where the tie line goes to the wrong parcel (TableStart Editing). 10. When all is OK, delete the lines (they are only graphics). Use Edit Select All Graphics and then hit the Delete key.
46 NOTE: You probably dont want to save the parcel themes spatial edits at this point, especially if you have moved only a subset of parcels. Select Theme Stop Editing, and click No when asked if changes should be saved. Each invocation of Nearest Features resu lts in a new output .dbf table, which contains two columns: PID and UF-Ref erence. Combine (concatenate) these tables in a spreadsheet or database manager. Then, in ArcView, join the boatmoor themes attribute table with the new, combined table, using UFreference as the Join Item. This will attach the correct PID to each boatmoor feature. Immediately use Theme Convert to Shapefile to make a new shapefile, preserving the Join. Data Cleanup Sanity checking and editing soundings signage, boat, and mooring positions and attributes are best done when the fieldwork is fresh in the crews memory. A look at the feature positions over the background imagery (in HYPACK for soundings and in PathFinder Office and/ or ArcView for signs, boats, and moorings) should be the final part of each days work, except for file backups. [Very rarely, Pathfinder Office will be unable to open or process a DGPS rover file, reporting it corrupt. If the Check SSF Files utility can not fix the problem, try downloading the file again. If that fails, Trimble Tech Support may be able to recover the file. Consult the Trimble m anuals for contact information and send the SSF file to them as an E-mail attachment.] Soundings Cleanup Processing soundings using the procedur es described above will result in a distribution of data points suitable for display and for constructing channels to be used in the restriction analyses; that is data clumps around overpasses, shoals, or other places where the boat mov ed slowly will have been appropriately thinned. However, very rarely the DGPS will make obvious errors, manifested by soundings that are displayed in the wrong place, perhaps on land. These errors are not subtle, but readily apparent. The data collector should look carefully at the location of soundings over the ent ire study area. If such anomalies are observed, do not try to corre ct the situation by editing the sounding positions in a GIS. Rather, the affected part of the study area must be surveyed again. Note: Soundings collected in new canal systems or near inlets where storm events have caused shoreline changes since the background imagery was created may appear to be on land. Verify, as required. Remember, editing sounding positions is not acceptable Several error sources can affect depths measured by echo sounders. Common are excessively deep soundings caused by mu ltiple bounces of the transducer signal from the bottom, back to the boat hull, and off the bottom again. This results in doubling (or even quadrupling) the true depth. If t he sounder fails to
47 record a depth for a position, it may send a zero reading to the survey software. Raw soundings (before boat squat/settlem ent corrections) of exactly zero are always bogus, because sounders have minimum operating depths greater than zero. An initial step in cleaning up sounding dataafter creating the shapefile with thinned data point and all attributes, but before creating text files for tide correctionsshould be to select and delet e all data points with a Raw Depth 1 value of zero. In an ArcView view, ma ke the sounding theme editable (make it active and choose Theme Start Editing). Use the Query Builder tool to select the zero depths. Query: ( [Raw depth 1] = 0 ). Delete them by use of the Delete key. Construct appropriate queries and look cl osely at soundings with raw depths of less than approximately three feet. Delete if questionable, based on field notes and knowledge of actual minimum depths in a study area and the characteristics of the sounder(s) being used. Estimate the maximum depth reasonably expected in an area, and build a query to select all depths deeper than that val ue. Examine the selected (highlighted) soundings and delete them if appropriate. This will eliminate many, perhaps most, of the doubled or quadrupled readings. Apply a color-coded legend to the depths that makes changes in depth categories visually obvious. (For exam ple, the file depths_ft.avl, on the accompanying CD, provides a useful l egend. Note that the appropriate Values Field for it is Depth_ft, which is in uni ts of feet.) Then carefully examine the depths for sporadic, unlikely values. Si multaneously displaying depths from two different sounders can be very useful. Overall, the colors displayed from the sounders should be very similar. A series of points with differing colors from the two sounders should be investigated. Of ten, only one of t he two sounders will double, and the difference will be obvious. With reference to field notes and aerial photo annotations, digitize soundings to fill in gaps caused by shoals or loss of DGPS positions around buildings or under trees and bridges. Make the theme editable, and then use the Draw Point tool to create points at the appropriate locations. In the themes attribut e table, enter the depth and the time of each sounding. Display the soundings along with a line s hapefile of the waterways planned for surveying to ensure no areas have been missed. Signage Cleanup Most signage features are mapped using a laser rangefinder with the DGPS data logger. It is possible to miss a sign with the rangefinder and grab the position of a
48 background object. Such misses should be readily seen when the signs are displayed over the background imagery. In most cases, field personnel can locate the correct position on the imagery. If so, simply make the theme editable, select the errant sign, and, using the Pointer tool (solid black arrow cursor), slide it into place. Deliverable signage maps will require a m eaningful legend, sho wing the different sign messages by symbology. Such a legend is also helpful in cleaning up the signage shapefile. Signs.avl (on the CD) app lies specifically to signage mapped in Lee County, but it can be modified to suit actual signs in other areas. The DGPS has occasionally m apped all the signs of a rover file in the wrong place, a mile or more from the correct positions. The array of signs was the correct size and shape, just in the wrong pl ace. Selecting them all and carefully sliding them cross country to the right place has sufficed for correction. Boats and Moorings Cleanup Boat and moorings rover files are subject to the same kinds of positional errors mentioned above for soundings and signs. Again, the rangefinder may miss the intended feature, or the DGPS might make gross errors. The correct position of a boat or mooring along a canal or mari na pier may often be determined by the logging times. Boats and moorings are lar ge objects, so slidi ng the features back to the approximate locations on the aerial, within the feature dimensions, is a good solution.
49Channel and Boat Restriction Analysis The purpose of the channel and boat restri ction analysis is to determine the degree of accessibility for each boat and to determine the location and magnitude of corresponding channel rest rictions. The detailed, comparative analysis of water depth and boat draft re lations provides a comprehensive overview of channel conditions and t he geographic distribution and severity of waterway restrictions. The analysis delineates and quantifies, at a 0.5 ft resolution, levels of boat accessibility to deep, open water1, and the location and extent of channel depth restrictions. Boat access refers to the difference between a boats draft and the depth of the sha llowest downstream channel segment, at MLLW, that it must pass to gain access to open water. The analysis is accomplished using Arc Macro Language scripts (AMLs) programmed to run on UNI X ArcInfo and requiring the PERL language be installed. In most instances the scripts can run on ArcInfo in Windows; however, the analysis.aml has proved to be more r obust on UNIX. The scripts are located on the accompanying CD-ROM in the AMLS subdirectory. This following section contains exampl es showing how to use commands. The commands themselves and any additional responses typed in by the user appear in bold text: Arc: build boats points Arc: describe boats Creation of the Trafficshed Coverage The term trafficshed is used to define a boat source area that contains a concentration of boats that use a common channel, exclusive to the trafficshed, to gain access to secondary access channels and, ultimately, to deep, open water. The number of trafficsheds that are defined for a particular study will depend on the number of boat so urce areas that are delineated. Figure 8 shows four defined trafficsheds on Estero Isl and, Lee County. The boundaries of each trafficshed polygon are drawn (in ArcEdit or ArcView) so that all boats, moorings, depths, and signs that pertain to t he trafficshed are included within the boundaries of the trafficshed polygon. 1 Deep, open waterdefined as a function of vessel draftbegins at that location in the transit of a vessel, from its berth, beyond which the vessel is no longer restricted to a channel because of environmental or depth limitations. The location of what is considered deep, open water also can be associated with the aggregat ed draft characteristics of a trafficshed or a boating region.
50 Figure 8. Trafficshed definitions. The trafficshed polygon coverage will contain the following items: NAME WIDTH OUTPUTTYPE N.DEC AREA 4 12 F 3 PERIMETER 4 12 F 3 TRAFSHEDS# 4 5 B TRAFSHEDS-ID 4 5 B TRAFSHED 4 6 B NAME 50 50 C BOATS 4 4 I RESTBOATS 4 4 B MOORINGS 4 4 I SIGNS 4 4 I DERELICTS 4 4 I NORMDREDGEVOL8 10 F 2 ADDDREDGEVOL 8 10 F 2 REGION 4 2 B The non-standard ArcInfo Poly gon Attribute Table (PAT ) items are defined as follows:
51 1) TRAFSHEDtrafficshed identif ication number (user defined). 2) NAMEwhere available, the name given to a trafficshed (user defined). 3) BOATSnumber of berthed boats in a trafficshed at survey time. 4) RESTBOATSnumber of restricted boats contained in a trafficshed at survey time. 5) MOORINGSnumber of moorings c ontained in a trafficshed at survey time. 6) SIGNSnumber of signs contain ed in a trafficshed at survey time. 7) DERELICTSnumber of derelict ve ssels contained in a trafficshed at survey time. 8) NORMDREDGEVOLestimated dredge vo lume (cubic yards) to achieve normal depth clearance within the tr afficshed (MLLW = 0 ft datum). 9) ADDDREDGEVOL the estimated dredge vo lume (cubic yards) to achieve additional depth clearance within the tr afficshed, which requires a one foot clearance between the lowest poin t of boat and channel bottom. 10) REGIONin some instances, a study area may be divided into different boating regions, based on the primary routes that boats are assumed to travel to reach open, bay waters. Boat s are assigned to a primary route to facilitate the analysis of channel and boat restrictions. The only item that needs to be assigned prior to analysis is TRAFSHED. The remaining items are assigned when the analysis has been completed and checked. Preparation of the Channel Centerline Coverage Create Channel Centerlines two coverages are required as input for the analysis AML: channels and boats. The channel coverage is an arc coverage that is created from the depth point coverage using LINE.AML (on CD-ROM). Before running LINE.AML to create channel centerlines, a copy of the depth point coverage must be BUILT with the POINT and LINE options. The coverage should be given an obvious name, such as Chan nels. The followin g item must be added to the Arc Attribute Table (AAT) of the channels coverage: ITEM NAME WIDTHOUTPUTTYPE N.DEC MLLW+5 8 7 F 1 LINE.AML must be run from within Ar cEdit with the channel coverage as the EDITCOVERAGE, EDITFEATURE set to points, and DRAWENVIRONMENT set to points and arcs. It is necessary to create the channel centerlines in a downstream direction; otherwise the anal ysis will not perform correctly, as the analysis AML is designed to route boats fr om trafficshed interiors towards deep, open waters.
52 When creating the channel network, it is best to work on one trafficshed at a time. To guide the selection of depth points used in channel creation, the TEXTITEM command should be used to display the MLLW depth. Arcedit : TEXTITEM label mllw+5 Start at the upstream limit of the tra fficshed and work towards the outlet of the canal system or waterway. The AML proc esses two depth points at a time to create a channel segment bet ween them. Thus, the AML requires the user to select successive depth points in the downs tream direction. Once two points are selected, the AML will creat e a channel segment between them and calculate the segment depth as the minimum MLLW depth of the two depth points. The X and Y coordinates for the end points (nodes) of each channel segment are derived from the two depths points. Upon completion, the channel coverage shou ld be checked carefully to assure that channel segments are digitized in a downstream direction. The upstream node of a particular arc segment shoul d be the from-node and the downstream node should be the to-node. Proper arc di rection can be checked either on the display or by printing hardcopy maps of the centerline channe l system. Draw the channel network with arrows turned on (ArcEdit: DRAWENVIRONMENT ARC ARROWS; ArcPlot: ARCARROWS). Edit as required to flip arrows to the downstream direction (ArcEdit: FLIP). The depths assigned to each channel segment should be checked as well. This can be done by querying channels for depths outside the range of expected values such as negative or depths with a value of zero and by making plots with color-coded segments. Make Routes the next step is to assign the ar cs within the channel coverage to route systems. For most study areas onl y one route system needs to be created. However, there may be situations when it is desirable to create multiple routes. This would occur, for example, when t he travel paths leading from separate trafficsheds converge and follow a co mmon centerline to deep, open water. Boats will be assigned to a particular travel route. This assures that each boat follows the appropriate travel route dur ing the analysis process. The analysis AML is designed to ignore any arcs that ar e not assigned to a route system. This provides a mechanism by which channels can be delineated and, if desired, removed from the routing analysis. Figure 9 shows a portion of Estero Bay, in Lee County, for which three separate route systems were created. Starting from the upper left figure and proceeding clockwise, the first map shows all three routes, followed in succession by isolat ed views of routes 1, 2, and 3. Route systems are created in ArcEdi t, making the channel coverage the EDITCOVERAGE and arcs the EDITFEATURE. A subset of arcs that belong to a particular route are selected using an appr opriate selection option, such as SELECT PATH. Once the subset is selected, then the MAKEROUTE command
53 is used and an appropriate name is chos e for the route subclass, such as route.travel. Arcedit: MAKEROUTE
54 Figure 9. Example travel routes in Estero Bay, Lee County, Florida. A series of prompts and dialog boxes request that the user: 1) Select the channel cover fr om a list of arc coverages. 2) Select the boat cover from a list of point coverages. 3) Select the route system. 4) Identify which item contains the boat draft (normally DRAFT). 5) Identify which item contains the trafficshed number (normally TRAFSHED). 6) Whether to reset the analysis item s in the boat and channel coverages. If the channel coverage contains more t han one route, the user will be prompted to identify a boat event file. The creation of a boat event file is only necessary when multiple routes have been defined, as shown in Figure 9. The analysis.aml selects each boat in succession following in formation from the user: the names of two input coverages: the arc coverage t hat contains the channel segments, and the point coverage that c ontains the boat features. Once the analysis AML has completed, t he results should be confirmed. This is done by visually checking, within ArcVie w or ArcInfo, the values that are calculated for the boat PAT and the channel AAT.
55 During the analysis, the following items ar e added to the point attribute table (PAT) for the boat coverage, and the item values are calculated for each boat feature: 1) ALLCONDEPTHthe controlling c enterline depth (feet ) outside of the trafficshed, reported to the nearest 1/2-foot and MLLW. A value of 99.9 indicates that the boat does not traverse any delineated channel segments located outside of the trafficshed in order to reach open bay water. 2) TSHEDCONDEPTHthe controlling centerline depth (feet) within the trafficshed, reported to the nearest 1/2-foot and MLLW. A value of 99.9 indicates that the boat was not assigned to a trafficshed. 3) TBLOCKAGEdefined as the diffe rence between boat draft and the controlling centerline depth within the trafficshed. For example, if boat draft equals 4.5 feet and the controlling depth is 3.0 feet, then the boat is restricted by 1.5 feet. A negat ive value indicates that b oat is not restricted. A value of 99.9 indicates that the boat was not assigned to a trafficshed. 4) ABLOCKAGEdefined as the differ ence between boat draft and the controlling centerline depth located outside of the boats trafficshed. For example, if boat draft equals 4.5 feet and the controlling depth is 3.0 feet, then the boat is restricted by 1.5 fee t. A negative value indicates that the boat is not restricted. 5) BLOCKAGEthe maximum depth rest riction presented to the boat by channel segments within t he trafficshed and outside the trafficshed. The blockage value is the maximum of the ABLOCKAGE and TBLOCKAGE attributes. During the analysis, the following items are added to the arc attribute table (AAT) for the channel coverage, and the item values are calculated for each channel segment: 1) BIGBOATUPSTRMthe vessel (draft) wit h the largest draft (feet) located upstream of the channel segment. A val ue of indicates the arc segment is not part of a principal travel rout e used in the restriction analysis. A value of .9 indicates that no boats are upstream of segment. 2) RESTRBOATCNTthe number of upstream boats that are restricted by the channel segment. 3) DREDGELevel of Restriction (feet ): Defined as the difference between channel segment depth (Item name: M LLW+5) and the maximum draft of vessels located up-channel. For exampl e, a channel segment with a depth of 2.5-feet will restrict a 3.5-foot boat located upstream by 1.0 foot. Upon completion of the analysis, the re sults are used to produce the final products as described in the next section.
57Products Deliverable products, based on the re sults of the Regional Waterway Management System include large-scale, la rge format map atlases; an ArcView application to reproduce the map atlases; a CDROM containing project databases; and a final report. Large Format Map Atlases Three multi-page, 1:2400-scale, large forma t (35 x 35) map atlases portray depths, boat drafts, signs, waterway restri ctions, and boat accessibility for saltwater accessible canals and waterw ays within a pr oject area. Bathymetry Atlas The bathymetry atlas contains depth points collected for centerline and adjacent shoals. Depths portrayed on each atlas page are those collected by project personnel, supplemented by depth points obtained from the USACE for Federally maintained waterways. The depth points t hat are collected according to methods presented in this manual are accurate to -foot and are corrected to MLLW. Boat Drafts/Bathymetry/Signs Atlas This atlas contains depth points accura te to -foot and co rrected to MLLW. The depths are presented in six classe s (ft) : <= 1, 1.5 or 2.0, 2.5 or 3.0, 3.5 or 4.0, 4.5 or 5.0, > 5.0. Depth points collected by projec t personnel, and portrayed in the bathymetry atlas, ar e supplemented by any avai lable depths obtained from the USCAE. Boats are presented in six draft classes (ft) : <= 1, 1.5 or 2.0, 2.5 or 3.0, 3.5 or 4.0, 4.5 or 5.0, > 5.0. Signs are presented in eight classes: speed regulation, hazard warning, resource protection, navigation guide, private ownership, government, business, and other. Analysis Atlas The analysis atlas contains plots of channel and boat restrictions. Channel restrictions are defined as the diff erence between a channel segment depth and the maximum draft of vessels located up-channel (upstream). For example, a channel segment with a depth of 2.5-feet will restrict a 3.5-foot boat located upstream by 1.0 foot, and is displayed in the atlas by a thick, color-coded line. The degree of channel restriction is portray ed in seven classes: No restriction; 0.0 feet, 0.5 foot, 1.0 foot, 1.5 feet, 2.0 feet, and greater than or equal to 2.5 feet. Boat Restrictions are defined as the difference between boat draft and the controlling centerline depth. For example, if boat dra ft equals 4.5 feet and the controlling depth is 3.0 feet then the boat is restri cted by 1.5 feet, and is portrayed in the atlas by a color-coded cross. Boat restrictions are portrayed in seven classes: No restricti on; 0.0 feet, 0.5 f oot, 1.0 foot, 1.5 feet, 2.0 feet, and greater than or equal to 2.5 feet. Each of the three atlases can be produc ed using ArcInfo AMLs included on the accompanying CD-ROM (/Products/MapAtlas es). The bathymetry atlas is
58 produced using depths-atlas.aml, the Drafts/Bathymetry/Signs atlas using alldata-atlas.aml, and t he analysis atlas using the analysis-atlas.aml. The AMLs are written to run on a UNIX system. Each AML needs to be edited in order to set directory locations for the required ArcInfo coverages and support files, such as credits, images, legends, and legend keys. The necessary support files are included on the CD-ROM. The AM Ls require USGS 1-meter DOQQs, and the DOQQ routine within the AML needs to be modified for each new project area. An ArcInfo polygon coverage that contai ns an index of map pages is required to run each AML. The page index coverage is created from a quarter-quad grid index of Florida t hat was obtained from the FDEP Technical Services Geographic Information Services web site and included on the CD-ROM (/Products/MapAtlases/qquadindex.e00). To create the page index for a project area, the relevant quarter quadrangles that encompass project field data (boats, moorings, depths, signs, and trafficsheds) are extracted from the FDEP coverage and each quarter quadrangle is then partitioned, using ArcInfo (or ArcView), into 16 equal area tiles. Each tile represent s 1/16th of a DOQQ and is labeled with the quadrangle name, the quadrangle quarter (NW, NE, SW, SE), the tile number (1 to 16), the Florida Department of Environment al Protection quadrangle number, and a user assigned page number that corresponds to the mapping extent for the series of 1:2400 thematic atlases. An example of the resultant page index coverage is in cluded on the CD-ROM (/Products/MapAtlases/qquadindexEXAMPLE.e00). To run any of the map atlas AM Ls use the following syntax: Arc: &run
59 needs to be converted to a shapefile and placed in the shapfiles directory (/ufatlas/shpfiles) and unrelated page indices from prior projects removed. Name the new page index shapefile according to the county or project area (e.g., lee.shp) where the project is being conducted. Include a field in the index theme attribute table that is named with the first letter of the shapefile filename followed by _id (e.g., for lee.shp the fieldname is L_id). This field needs to be populated with the index pag e numbers. Start the ArcView project and apply the inde x legend (/ufatlas/s hpfiles/index.avl) to the page index theme. Label the them e with page numbers using the special Label All tool, which is made available by setting its invisible property to False from the customize dialog. The label tool allows t he user to select the page number field and to set the label font. On ce the labels have been finalized, save and exit the project. Place uncompressed map atlas print files (.rtl) in a subdirectory named for the atlas with which they are associated (i.e Depths, Boats, or Analysis). This subdirectory is placed under the /uf atlas/atlases directory (e.g., /ufatlas/atlases/Boats). Map atlas filenam es that begin with a are associated with the Bathymetry atlas, those that begin with b with the Bathymetry/Boats/Signs atla s, and those with c with the Analysis atlas. Edit the project file in a text editor, su ch as NotePad, and make all references to file locations relative by removing the driv e letter. Save the edited project file and set the file permissions to read only. T he ArcView Map Atlas application is then installed on a computer by following the instructions contained in the Usernotes.doc (/ufatlas). Project data metadata files (/ufatlas/metadata) will need to be updated for each new project. The me tadata files are in html format and describe, in detail, the individual thematic layers fr om which the atlases were constructed. GIS Data Sets and Imagery At the completion of each project, t he background imagery and the GIS data sets created during project implementation are packaged in an ArcView project file (.apr) for delivery. An example of the st ructure of the data CD is contained on the CD-ROM that accompanies the manual. Each data set is packaged in two formats: 1) ArcInfo export files contained in the Ar cExport directory, and 2) ArcView shapefiles contained in the AVShape directory. The ArcView project (e.g., /ProjectDataCD/leephase1.apr) is created with a view containing all data sets and imagery. T he imagery included wit h the example are JPEG images and, thus, require that the J PEG (JFIF) extension be invoked from the available extensions. The data sets and imagery that are norma lly included are described as follows:
60 a. DEPTHSinformation on depths points recorded for all channel centerlines and approaches to boati ng facilities and referenced to the navigation datum, MLLW, and repor ted to the nearest 1/2 foot. b. CHANNELSboating access channels, classified according to depth (nearest 1/2-foot; MLLW) and degree of restriction. c. BOATSboats berthed in the water or stored on salt-water accessible parcels. Information includes boat ty pe, length, age, make and model, draft, facility, mooring type, the date the boat was surveyed, and the level of restriction. d. MOORINGSmoorings, including information on facility, mooring type, and the date the mooring was surveyed. e. DERELICTSderelicts vessels, including information on condition, whether the vessel is beached or afloat, percent of submersion, and the date the vessel was surveyed. f. SIGNSboat-related signs in th e water and along the waterfront and visible to boaters. Information incl udes site, type, message, status, condition, and the date the sign was surveyed. The signs are grouped into the following classes: hazard warning, municipal mooring, navigation guide, private ownership, resource protection, and speed regulation. g. TRAFFICSHEDStrafficsheds (navigab le waterways that serve as boat source areas). Trafficsheds serve as units of analysis and allow the county to prioritize waterway management e fforts. Information provided for each trafficshed includes the numbers of boat s, moorings, signs, and derelict vessels that were present in the traffi cshed at the time of the field surveys. Trafficsheds range from complex canal systems to short, one-segment channels that provide access fr om shore to open-bay waters. h. ATLASINDEXtiles constructed fr om a digital map index of USGS quarter quadrangles. Each tile repres ents 1/16th of a quarter quadrangle and is labeled with the quadrangle name, the q uadrangle quarter (NW, NE, SW, SE), the Florida Departm ent of Environmental Protection quadrangle number, and a page number that corresponds to the project mapping extent. i. Background imagery derived from USGS 1-meter digital orthophoto quadrangles is included in the dire ctory labeled Images. Each image is provided JPEG formats, and the JPEG images are available in 1, 3, and 6 meter resolutions. Metadata is provided for all data sets in HTML format (/Products/ProjectDataCD/Metadata). Final Report A final report presents the Regional Waterway Management System Findings. Sections in the report include: Introduc tion, Background, Information on the data sets collected during the field work, an expl anation of the data products, project results, special management considerations for the proj ect area, and conclusions and recommendations. The bibliography that accompanies this manual contains
61 citations for past reports, which can be re ferred to when preparing future reports (Antonini and Box 1996; Antonini, Swett, Schulte, and Fann 1998; Swett, Antonini, and Schulte 1999; Swett, Fann, Antonini, and Carlin-Alexander 2000, 2001).
63References Antonini, G.A., R. Swett, S. Schulte and D. Fann. 1998. Regional Waterway Management System for South Sarasota County. TD-1. Gainesville, FL: Florida Sea Grant College Program. Antonini G.A., and P. Box. 1996. A R egional Waterway Systems Management Strategy for Southwest Florida. TP-83. Gainesville, FL: Florida Sea Grant College Program. Coastal Oceanographics, Inc. n.d. HYPA CK Users Manual. Middlefield, CT: Coastal Oceanographics, Inc. Florida Bureau of Comprehensive Plannin g. 1976. The Florida Land Use and Cover Classification System: A Tec hnical Report. Tallahassee, FL: State of Florida, Department of Administ ration, Division of State Planning. Infinities USA, Inc. 1999. Data Logger Users Manual 2.1. Daytona Beach, Florida: Infinities USA, Inc. National Ocean Service. 1999. NOS Hydrogr aphic Surveys, Specifications and Deliverables. April 23, 1999. Accessed on-line at http://chartmaker.ncd.noaa. gov/ocs/text/hsd-0.html Ocean Data Equipment Corporation. 2000. Bathy-500MF Survey Echo Sounder Owners Manual. Walpole, Massac husetts: Ocean Data Equipment Corporation. Standard Communications. 2001. Horizon DS 150 Digital Depth Sounder Owners Manual. Los Angeles, CA: Standard Communications. Swett, R.A., D.A. Fann, G.A. Antonini, and L. Carlin-Alexan der. 2001. Regional Waterway Management System for Lee County, Phase 2. TD-4. Gainesville, FL: Florida Sea Grant College Program. Swett, R.A., D.A. Fann, G.A. Antonini, and L. Carlin-Alexan der. 2000. Regional Waterway Management System for Lee County, Phase 1. TD-3. Gainesville, FL: Florida Sea Grant College Program. Swett, R.A., G.A. Antonini, and S. Schulte. 1999. Regional Waterway Management System for North Manatee County. TD-2. Gainesville, FL: Florida Sea Grant College Program. Trimble Navigation Limited. 1998a. TSC1 Asset Surveyor: Software User Guide. Revision A. Sunnyvale, CA: Tr imble Navigation Limited.
64 Trimble Navigation Limited. 1998b. Pro XR/XRS Receiver Manual. Revision A. Sunnyvale, CA: Trimble Navigation Limited. Trimble Navigation Limited. 1998c. DSM 12/212 Operation Manua l. Revision A. Sunnyvale, CA: Trimble Navigation Limited. Trimble Navigation Limited. 1995. Pro XL System Operation Manual. Revision C. Sunnyvale, CA: Trimble Navigation Limited. U.S. Army Corps of Engi neers. 2001. Engineering Manual, EM 1110-2-1003, Hydrographic Surveying. Washingt on, DC: Department of the Army.
65Appendices Equipment Specifications Bathy-500MF Multi-Frequency Survey Echo Sounder Depth Range: 0-15, 0-30, 0-60, 0-120, 0-240, 0-480, 0-1920 Feet; 0-10, 0,20, 0-40, 0-80, 0-160, 0-640 Meters Phasing: 0-120, 60-180, 120-140, 180300, 240-360, 300-240, 360-480 Feet, Auto; 0-40, 20-60, 40-80, 60-100, 80-120, 100-140, 120-160 Meters, Auto Accuracy rating: 0.5 percent Chart Record: 8.5 inch X 90 f eet high-contrast thermal paper Digital Display: LCD (4 line X 16 char acters) 0.25 inch characters; Depth display: 0.75-inch characters; Back-light ing: Electro-luminescent Resolution: 0.01 units for depths less than 100 mete rs; 0.01 for depths greater than 100 meters; 0.1 feet on all ranges Frequency: Any single frequency (user selectable & changeable via keypad) from these: 33Khz, 40Khz, 50Khz, 200Khz (Acoustic output=600 watts) Depth Alarms: Shallow and deep (selected by keypad) Sound Velocity: 4600-5250 feet/second (1393-1590 me ters/second); user selected by keypad Offset: 0 to +30 feet or meters (allows the user, via keypad, to adjust for the net sum of transducer depth and tide Geographic Position: NMEA-0183 GGA or GLL format for GPS/DGPS Data I/O Compatibility: COM1 provides bi-dir ectional interface to PC or other peripheral device; this port accepts exte rnal annotation from external sources such as hydrographic software. This port also allows remote control of all echo sounder functions using Ocean Datas Windows 95/98/NT based software. Com2 accepts GPS/DGPS i nputs and provides additional (from COM1) data outputs. Data Outputs: ODEC PMS dt (True D epth & Status); Atlas DESO-25; Odom Digitrace; Odom Echotrac; NMEA DBT; NMEA DBS Input Power: 11-30 volts d.c. (1.5 amps @ 12v. 0.5 amps @ 30v.) Dimensions: Height (including handle) 19 inches; width 17.5 inches; depth 9 inches Weight: 35 lbs (recorder with transducer) Operating Temper ature: -10 oC to +50 oC / Humidity 95% non-circulating Bathy-500MF Transducer (P/N P01540) Resonant Frequency: 208 KHz Nominal Impedance: 50 ohms Beamwidth (@ 3 dB point): 8 degrees Cable: 30 feet (with pl ug to mate with recorder) Housing Material: Brass ( with urethane acou stic window) Piezo Material: Barium titanate
66 Horizon DS150 Single-beam Echo Sounder Power Supply: 0.7 to 16.6 VDC 15 mA nominal, 35mA with backlight on Operating temperature: 32o to 114o F (0o to 45o C) Accuracy rating: 2 percent Size of display: 4.4 x 4.4 x 1 inches (112 x 112 x 20 mm) Overall depth: 1.4 inches (35 mm) behind panel Display type: Twisted Nematic (TN), gray background) Illumination: Red LED RF Interference: Less than 6 dB ma ximum quieting on any marine radio channel with 3 dB gain antenna within 1 meter of instrument head Depth: 3 to 400 ft, 1 to 120 meters, or -.5 to 67 fathoms Alarms: Shallow and deep water, Audio and LCD flag Display unit selection: Feet, mete rs or fathoms, keypad selectable Display damping: Three levels keypad selectable Keel Offset: Keel/propeller or waterline, 9.9 ft, 1.6 fathoms or 3.0 meters, user selectable trend indication NMEA outputs: DPT, DBT Proprietary Outputs: Alarm and Trend arrows Transducer: 201 kHz, 600 ohm 1500pF parallel capacitance Infinities USA Model 220 ultrasonic water level loggers Number of measurements in memory: 3906 User programmable interval: 1-readi ng/second to 1-reading/6 months User interface to Logger: PC or opt. HP 48GX or 48G+ calculator w/ software Data logger power: Four AA alkaline batteries Data logger battery life, typical: 4 years Data logger range: 18 feet Minimum target distance: ~16 inches Ranging environment: inside 1 1/ 4" to 3" PVC sch. 40 pipe Temperature compensation: 0F to 120F Humidity: to 100% Accuracy: +/1% of distance measured Resolution: ~0.04 inches or 1mm Ultrasonic Frequency: 49.7kHz Data download rate: 150 measurements per second Download medium: serial cable Hewlett-Packard 48GX storage: multip le data loggers, 40,000 measurements Trimble Pro XR Receiver Fully sealed, dustproof, wa terproof, shock resistant 1 Hz update rate Time to first fix <30 seconds, typical Size: 11.1 cm x 5.1 cm x 19.5 cm (4.4 x 2 x 7.7) Weight: 0.76 kg (1.68 lbs) Power: 5 watts (maximum)
67 Temperature: -30o C to 65o C (-22o F to 149o F) Operating -40o C to 85o C (-40o F to 185o F) Storage Humidity: 100% non-condensing Integrated GPS/ BEACON Antenna Right-hand, circular polarized; omni directional; hemispherical coverage Size: 15.5 cm diameter x 10.8 cm high (6.1 x 4.2) Weight: 0/49 kg (1.08 lbs) Temperature: -30o C to 65o C (-22o F to 149o F) Operating -40o C to 85o C (-40o F to 185o F) Storage Humidity: 100% fully sealed Case: dustproof, waterproof, shock resistant Trimble DSM212H Integrated GPS/MSK Receiver Standard Features 12-channel GPS receiver Integrated GPS and dual chann el MSK beacon receiver Outputs positioning reports at 1, 5, or 10 Hz Isolated power supply Positioning based on carrier-phase filtered L1 pseudo-ranges Two programmable RS-232 serial ports: o NMEA-0183 output or RTCM SC-104 output o RTCM SC-104 input o TSIP input and output 1PPS output Windows configuration software DSM212 operation manual Compact L1 GPS and MSK H-field loop antenna 15 meter RG58 antenna cable Power/data cable 12Pin to data cable Performance Characteristics 12-channel, parallel tracking, L1 C/A code with carrier phase filtered measurements and multi-bit digitizer Differential speed accuracy: 0.1 knt (0.1 mph, 0.16 km/h, 5.6 cm/s) Differential position accuracy: Less t han 1 meter horizontal RMS (at least 5 satellites, PDOP < 4 and RTCM SC-104 standard format broadcast from a Trimble DSM12RS or equiva lent reference station Time to first fix: < 30 seconds, typical NMEA messages: ALM, GGA, GLL, G SA, GSV VTG, ZDA, RMC, MSS Physical Characteristics Size: 14.5cm W x 5.1 cm H x 19.5 cm D Weight: 0.76kg (1.68 lb) Power: 5W (max), 10 to 32 VDC
68 Operating temperature: -30 oC to +65 oC Storage temperature: -40 oC to +85 oC Humidity: 100% condensing, unit fully sealed MSK Beacon Dual-Channel Receiver Frequency Range: 283.5 KHz to 325.0 KHz Channel spacing: 500 Hz MSK modulation: 50, 100 & 200 bits/second Signal strength: 10 V/meter minimum @ 100BPS Dynamic range: 100 dB Channel selectivity: 70 dB >500 Hz offset Frequency offset: 17 ppm maximum 3rd order intercept: +15 dBm @ RF input (min. AGC setting) Beacon acquisition time: <5 sec, typical AMREL Rocky II Plus CPU: Intel Pentium, 366 MHz Pentium II Ram Memory: 64MB SDRAM standard Storage: Removable 2.5 HDD (available 6GB up to 10GB); Removable 3.5 1.44MB FDD Display: 12.1 800 x 600; AGP compli ant 128-bit video engine with 256-bit bus 2.5MB embedded SDRAM Keyboard: 89-key KB standard keycap with dust cover and Windows 95 keys ready; PS/2 compatible touchpad Power System: Removable 10.8V 4500m AH Lithium ion primary battery; secondary 10.8V 4500mAH Lithium ion battery pack (DR202 compatible) swappable with FDD; smart battery and smart charger I/O Ports: 2S, 1P, CRT, external kb, eternal FDD, Fax/Modem (RJ-11), LAN (RJ-45), Audio, PS/2 mouse, USB, port replicator; 2 PCMCIA type II slots or 1 type III slot; LAN, radio modem etc, Cardbus and ZV port support; IrDAcompliant infrared transceiver (f ast IR 4 MB/sec transfer rate) Dimension: 312 mm x 246 mm x 62.5 mm; Weight approximately 4.7 kg; rain and dust proof, shock resistant structure; magnesium case Dell Dimension XPS T750MHz Pentium III 768MB DSRAM Memory with ECC V.905/56K PCI DataFax Modem 8x/4x/32x CD-RW 32MB NVIDIA geForce Plus AGP Graphics Card 18GB 10K SCSI Hard Drive 3. Floppy Drive 3Com US Robotics 3C905C-TXM 10/100 Remote Wake Up Nic
69 Advantage Range Finder Dimensions 8.5 H X 4. 5 W X 7.5 L (inches) o (21.5 X 11.5 X 19 centimeters) Weight 4.5 lbs. (2.1 kg.) Laser Eye Safety: Class 1 (21 CFR 1040) o Beam Divergence 3 mrad Wavelength: 905 nm o Acquisition Time: 0.4 seconds Distance Reflectorless:10,000. ft (2 m) Measurement Reflector: 10,000 ft. (2--9,188 m) o Accuracy: 0.5 ft (15.3 cm) 3 Sigma Compass Type: Strapped Down Magnetometer Azimuth Range: 0.0 to 359.9o Measurement Accuracy: 1.0o RMS (when level) 1.5o RMS (when tilted) o Repeatability: 0.3o Inclination Type: Dual-Axis, Fluid Measurement Range: 50o o Accuracy: 0.4o o Repeatability: 0.3o Communications Type: RS-232 at standard baud rates Internal Data Type: PCMCIA Type II SRAM Recording Power Voltage: 6 VDC Requirements Current: 400 mA o Battery Type:6 Volt NiCad Displays Rear Panel: Back lit 4 line x 20 character LCD o Head Up Display: 1 line x 4 character LCD, reticule Environmental Temperat ure, Operating: -22o F to +140o F o Temperature, Storage: -40o F to +176o F o Enclosure: Water Resistant, Ruggedized
70Survey Tide Correction Program Conceptual Description The Survey Tide Correction program de veloped in the University of Florida Coastal and Oceanographic Engine ering Department by Bill Mill er under the direction of Dr. Max Sheppard consists of three Fortran 90 programs. The basic program is survcorr.f90 which performs th e linear interpolations and corrects the survey data. The other programs, baseline1.f90 and baseline2.f 90, may be used to provide SURVCORR with its baseline files. The basic concept is to provide a means of correcti ng a survey of water depth within a winding canal or river system using a limited amount of tidal data. To do this a baseline of correcting reference points is c onstructed along the survey path within the system. In an ideal case, tide gages would be located at each baseline point and the survey could be corrected using a linear inte rpolation to the two gages nearest to the survey point. However, setting up so many tide gages is not practical. Ther efore, a baseline tide data file is constructed using two gages at either end of the system. The data is interpolated by program BAS ELINE2 based on the distance of the point from each gage. The baseline data is then used to corre ct the survey data. By using this baseline method, the distance between the gages within the winding path of the system may be considered, rather than the direct distance from the survey point to the gages. This direct distance will likely cut across the system and not reflect the true distance seen by the tide as it propagates along the baseline path. Thus, the baseline points are best located at the corners and bends in the system and the file describing the locations must list the points in sequence along the path of the system. The diagram below illustrates such a baseline.
71 canal system bay Tide Gages baseline points baseline Fig. 1, Canal System and Baseline Development If a branch to the canal system exists, a branch to the main baseline may be developed using the BASELINE1 program. The figure below illustrates this situation. canal system bay main baseline branch canal branch baseline Three Points required by BASELINE1 program Fig. 2, Branch Canal Case
72 The three baseline points are used to determine a water surface slope (time dependent). This slope is then applied along the branch baseline to determine the appropriate tidal corre ction with distance. If the tide is the same throughout the system, using a single baseline point in SURVCORR will result in a direct interpolat ion of the survey to this one point. In other words, only the time will be considered and interpolated and not the distance from the point. Instructions for Correcting a Survey A. Correction between two tide gages 1. Divide the survey data into appropri ate paths and format in an ASCII file described under the SURVCORR Progr am section of these instructions. 2. Per Fig. 1, plot a baseline on a chart of the survey area and record the locations of each point. The first and final points of the baseline should be tide gages. Each bend and corner in the canal system should be marked by a baseline point. Record th ese points in an ASCII da ta file described under the SURVCORR Program secti on of these instructions. 3. Use the BASELINE2 program to interpolate the tide data from the two tide gages and develop the Baseline Tide Data file used by the SURVCORR program. 4. Use these files as the inputs to the SURVCORR program described under the SURVCORR Program sec tion of these instructions. 5. The output file of the SURVCORR pr ogram should be examined to verify reasonableness of the corrections made to the survey data. B. Corrections to a canal branch 1. Per Fig. 2, determine the three main baseline points to be used in the BASELINE1 program and build their lo cation and data files. These files must have the form described under the BASELINE1 Program section of these instructions and be saved in ASCII format. 2. Plot a branch baseline on a chart of th e survey area and record the locations of each point. The first point must be the middle point of the three points chosen above. Each bend and corner in the canal system should be marked by a baseline point. Record th ese points in an ASCII da ta file described under the BASELINE1 Program secti on of these instructions. 3. Use these files as inputs to the BAS ELINE1 program. The output of this program will be the Baseline Tide Data file used by the SURVCORR program.
73 4. Use the Baseline Tide Data from (3), the Baseline location file from (2) and the survey data file as the inputs to the SURVCORR program described under the SURVCORR Program s ection of these instructions. 5. The output file of the SURVCORR pr ogram should be examined to verify reasonableness of the corrections made to the survey data. C. Corrections to a system with one tide gage If only one tide gage is used, no reference exists for how the tide varies with distance. In this case, the survey cannot be corrected fo r distance. Use the tide gage location and tide data as the only baseline point and repeat steps 4 and 5 of section A above. SURVCORR Program Input Files This program requires 3 input files. 1. Survey Data File This is the actual survey data file to be corrected. The file must be in 4 colu mns with two column headers. 44444 33333 22222 11111 depthyxidtime depthyxidtime depthyxidtime depthyxidtime The time should be in a continuous sequential format (i.e. seconds, minutes or hours) from a common reference time. Depth must be measured from the waters surface, positive downward. 2. Baseline Location File This file locates (i n x, y coordinates) the baseline points used to interpolate and correct the survey data. The file must be in three columns with two column headers. 444 int 333 int 222 int 111 int yx number po yx number po yx number po yx number po The point number must be an integer value, but will not be used in the calculations. The x and y coordinates must have the same reference as the survey da ta. The rows of this file correspond to the
74 location of the tide data in the columns of the Tide Data File described below. 3. Baseline Tide Data File This file contains the tide information used in the correction calculation. Eith er the BASELINE1 or BASELINE2 programs described later may generate the file. If the baseline points consist only of known tide gages, th e data developed from these gages may be used. Only one time column may be used, therefore actual tide gage data should be interpolated to this common time series. The file has the following format, again with two column headers. 24144 23133 22122 21111 time time time time The time must have the same form and refere nce as the time in the survey file. The time series must also precede the minimum survey time and exceed the maximum survey time. The value corresponds to th e tide level at each baseline point (by column) and should be referenced to the desired vertical datu m (i.e. NGVD, MTL, etc.). The interpolation will subtract the appropriate tide level from the survey. In other words, at a high tide level ( > datum, i.e. positive), the program will subtract the tide level from the survey depth. At a low tide level ( < datum, i.e. negative), the program will add the absolute value of the tide level to the survey depth. Output File The program output file will have the following form. 4 4 4444 3 3 3333 2 2 2222 1 1 1111 depth corrected depth original yxidtime depth corrected depth original yxidtime depth corrected depth original yxidtime depth corrected depth original yxidtime The left five columns will be identical to th e survey file described in (1) above. The sixth column will contain the corresponding survey depth corrected for the tide.
75 Single Point Baseline Construction Program (BASELINE1) This program will interpolate the tide data, based on distance, for a baseline which branches off of a main base line. If only one baseline point is used, distance will not be used in the interpolation, only time. In this case, the entire system will be assumed to have the same tide. Input Files This program requires 3 input files. 1. Three Point Tide Data File The three points used here will typically be chosen from a baseline file previously constructed from the BASELINE2 program. The file has the following format with no column headers. 3424144 3323133 3222122 3121111 time time time time The time must have the same form and reference as the time in the survey file. The time series must also precede the minimum survey time and exceed the maximum survey time. The value corresponds to the tide level at each baseline point (by column) and should be referenced to the desired vertical datum (i.e. NGVD, MTL, etc.). 2. Three Point Baseline Location File This file locates (in x, y coordinates) the three baseline points whose tide data was input in (1) above. The file must be in three columns without column headers. 333 int 222 int 111 int yx number po yx number po yx number po The point number must be an integer value, but will not be used in the calculations. The x and y coordinates must have the same reference as the survey data. The rows of this file correspond to the location of the tide data in th e columns of the Tide Data File of (1) above. 3. Baseline Location File This file locates (in x, y coordinates) the new baseline points. These new baselin e points must begin with the middle (number 2) point in the thr ee-point list above (i.e. point number1 of this file is point number2 of the above file).
76 444 int 333 int 222 int 111 int yx number po yx number po yx number po yx number po Output File The program output file will have the following form. 24144 23133 22122 21111 time time time time This file corresponds to th e Baseline Tide Data File described in the SURVCORR program and may be used directly in this program. Two Tide Gage Baseline Construction Program (BASELINE2) This program will interpolate the tide data for a set of baseline points located between two tide gages. The in terpolation will be a weighted linear interpolation based on the dist ance between the two gages. Input Files This program requires 2 input files. 1. Tide Gage Data File This file contains the actual tide information used in the interpolation calculation. On ly one time column may be used, therefore the time for each tide gage data should be interpolated to this common time series. The file has the following format, again with two rows of column headers. 24144 23133 22122 21111 time time time time
77 The time must have the same form and refere nce as the time in the survey file. The time series must also precede the minimum survey time and exceed the maximum survey time. The value corresponds to the tide le vel at each tide gage (by column) and should be referenced to the desired ve rtical datum (i.e. NGVD, MTL, etc.). The SURVCORR program will subtract the appropriate tide level from the survey. In other words, at a high tide level ( > datum, i.e. positive), the program will subtract the tide level from the survey depth. At a low tide level ( < datum, i.e. negative), the program will add the absolute value of the tide level to the survey depth. 2. Baseline Location File This file locates (i n x, y coordinates) the baseline points used to interpolate and correct the survey data. The file must be in three columns with two rows of column headers. 444 int 333 int 222 int 111 int yx number po yx number po yx number po yx number po The point number must be an integer value, but will not be used in the calculations. The x and y coordinates must have the same reference as the survey data. The first and last point in this file s hould be the two tide gages from the Tide Gage Data File of (1). The first point corresponds to the firs t data column (i.e. not the time column) of the Tide Gage Data File and the last poi nt corresponds to the second data column. Output File The program output file will have the following form. 24144 23133 22122 21111 time time time time This file corresponds to th e Baseline Tide Data File described in the SURVCORR program and may be used directly in this program.