Mark Hansen 2000 version 1 text files http://sofia.usgs.gov/projects/bathymetry/ The maps of the tracklines are linked to the corresponding data sets which contain values for X (easting), Y (northing), Z (elevation), and the Root Mean Square (RMS) error Detailed, high-resolution maps of Florida Bay mudbank elevations are needed to understand sediment dynamics and provide input into water quality and circulation models. The bathymetry of Florida Bay has not been systematically mapped in nearly 100 years, and some shallow areas of the bay have never been mapped. Numerical circulation and sediment transport models being developed for the South Florida Ecosystem Restoration Program are being used to address water quality issues in Florida Bay. Digitizing the historical shoreline and bathymetric data for comparison with modern data provides information on sedimentation rates within the Bay. 1889 1999 ground condition Complete None planned -81.11667 -80.36667 25.25 24.733333 none bathymetry hydrology mapping geography ISO 19115 Topic Category environment imageryBaseMapsEarthCover inlandWaters oceans 007 010 012 014 Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, DC, National Institute of Standards and Technology United States US U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, DC, NIST Florida FL Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology Miami-Dade County Monroe County USGS Geographic Names Information System Blackwater Sound Buchanan Keys Calusa Keys Clive Key Flamingo Florida Bay Everglades National Park Grassy Key Joe Bay Long Key Lower Matecumbe Key Pelican Keys Plantation Key Rock Harbor Sandy Key Tavernier Upper Matecumbe Key West Lake none Schooner Key Central Everglades Florida Keys none The U.S. Geological Survey must be referenced as the originator of the data set in any future products or research derived from these data. Mark Hansen U.S. Geological Survey mailing and physical address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 x 3036 727 803-2030 mhansen@usgs.gov http://sofia.usgs.gov/publications/ofr/00-347/1890trk.html location of 1890's tracklines GIF http://sofia.usgs.gov/publications/ofr/00-347/1990tk.html location of 1990's tracklines GIF Nancy T. DeWitt assisted in the bathymetric surveys and data processing. L. Thornton processed the historical data and provided GIS support. Data are in ASCII tabular text files Hansen, Mark DeWitt, Nancy T. 2000 report USGS Open-File Report OFR 00-347 St. Petersburg, FL U.S. Geological Survey http://sofia.usgs.gov/publications/ofr/00-347/ not applicable No data were collected for the Lake Ingraham and Madeira Key quads in 1890. For data format consistencies, RMS values for the 1890's data set are equal to 0.0. The horizontal positions of each data point were transformed from Latitude/Longitude to UTM (Zone 17) XY coordinates using NOAA/NGS software UTMSv1.0. For the 1990 data record epoch intervals were 1 second for both base station and rover receivers. Precise positions for each epoch were computed using Ashtech Precise Differential GPS Navigation and Surveying (PNAV) v. 2.0 software. PNAV provide a root mean square (RMS) value for each epoch. For this study, an RMS value of 0.08 cm or less was considered reasonable. An RMS value of 1.0 indicates that the GPS ambiguities were unresolved, and that the depths were determined by a tie-line best-fit method. 0.05 unavailable For data format consistencies, RMS values for the 1890's data set are equal to 0.0. Vertical positions were referenced to MLW (Mean Low Water). For 1990 data, vertical positions were converted from ellipsoid height to orthometric height using NOAA/NGS softwre GEOID96, where orthometric height is considered to be equal to NAVD88. According to NOAA tidal datum information, NAVD88 is approximately 0.41m (1.35 ft) above MLW in the Florida Bay area. The 1.35 feet average is calculated using the elevation information from several tidal benchmarks throughout the Florida Keys. These tidal benchmarks are published by the National Geodetic Survey and can be located on their website http://www.ngs.noaa.gov/cgi-bin/ngs_opsd.prl/. Five tidal benchmarks were chosen from four different U.S. Geological Quadrangle locations including Blackwater Sound, Plantation Key, Long Key and Grassy Key. To compare the 1890's values to NAVD88 add 1.35 ft. to the depth values. The historical bathymetric data obtained form NOAA/NOS archives were digitized using an Altech Digitizer. The data was georeferenced from the digitizer coordinates to geographic coordinates (latitude and longitude) using archived NGS control points on NAD 83. 199910 Mark Hansen U.S. Geological Survey mailing and physical address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 x 3036 727 803-2030 mhansen@usgs.gov Florida Bay was mapped by using a shallow-draft boat equipped with a high-precision Global Positioning System (GPS) coupled with a high-precision depth sounder. To accomplish this task, SANDS (System for Accurate Nearshore Depth Surveying) was developed by Mark Hansen and Jeff List of the US Geological Survey. SANDS utilizes differential GPS receivers, a digital fathometer, a heave-roll-pitch sensor, and a shallow-draft boat. The SANDS system is accurate to approximately 4 cm horizontally and 8 cm vertically and collects data in water depths as shallow as 30 cm. To achieve this accuracy, the boat's roving distance from any one GPS reference receiver location must be within a 10-kilometer radius. Data was collected on a USGS 7.5-minute quadrangle-by-quadrangle basis, proceeding westward from Blackwater Sound. The trackline spacing varied depending upon the relief of the sea floor; that is, closer spacing adjacent to mudbanks and wider spacing in the basins. Tracklines were surveyed in a north-south orientation, and crossings (intersecting tracklines) were surveyed in an east-west orientation. Crossing lines are critical because they served as a check on the accuracy of the system. In theory, data values at the crossing should be exactly the same. In reality, this is not always the case due to random errors of each sensor. Eighty-five percent of the crossings in this data set were within +/- 6 cm with the balance within +/- 20 cm. Ideally, crossings are made at the end of the survey day; however, some of the crossings were made months and even years after an area was initially surveyed. The results are very good considering the soft bottom characteristics of Florida Bay. Bathymetric positions for this study were derived using differential GPS techniques on 10-km baselines or less. One or more GPS reference stations (base stations) were continuously recording full-phase carrier data while the boat surveyed. A rover GPS receiver on the boat was simultaneously recording carrier information. Geodetic control in Florida Bay was lacking in number and geometric strength. In order to accomplish centimeter vertical accuracy, additional geodetic control needed to be established within the Bay. Thirteen new temporary ground-control points or benchmarks (surveyed to within 1 cm to 2 cm accuracy) were established throughout the Bay for use as reference receiver sites. The thirteen benchmarks were surveyed using Ashtech Z-12, 12 channel dual-frequency GPS receivers. Full-phase carrier data were recorded on each occupied benchmark in Ashtech proprietary BIN format with daily occupations ranging from 6 to 12 hours. BIN files were then converted to RINEX-2 format and position determined by the National Aeronautics and Space Administrations (NASA) Jet Propulsion Laboratory GIPSY system software. The GIPSY derived positions were provided in ITRF96 coordinate system for each (daily) occupation. Using National Oceanic and Atmospheric Administration/National Geodetic Survey (NOAA/NGS) software HTDPv2.3, ITRF96 positions were transformed to NAD83/GRS80 positions. The computed daily positions were then averaged to derive a final benchmark location and elevation. Daily outliers greater than 0.05cm (in the vertical component) from the average were not included in the final average. 199910 Nancy DeWitt U.S. Geological Survey Marine Geologist mailing address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext. 3058 727 803-2030 ndewitt@usgs.gov Florida Bay Universal Transverse Mercator 17 0.9996 -81 0 500000 0 Coordinate Pair 0.01 0.01 meters North American Datum of 1983 Geodetic Reference System 80 6378137 298.257 North American Vertical Datum of 1988 0.01 meters Explicit elevation coordinate included with horizontal coordinates The data contain the easting and northing in meters for UTM Zone 17, NAD83/GRS80; elevation in meters relative to NAVD88, and RMS value in meters, computed from Ashtech PNAV software for each point collected in each quad USGS personnel Heather S.Henkel U.S. Geological Survey mailing address

600 Fourth St. South

St. Petersburg FL 33701 USA 727 803-8747 ext 3028 727 803-2030 hhenkel@usgs.gov 1890 and 1990 data There are no warranties implied or explicit for the data. ASCII 8.1 http://sofia.usgs.gov/publications/ofr/00-347/data.html Data may be downloaded from the SOFIA website none 20080402 Heather Henkel U.S. Geological Survey mailing and physical address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext 3028 727 803-2030 sofia-metadata@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998