Hansen, Mark, 2000, High-Resolution Bathymetry of Florida Bay: U.S. Geological Survey, St. Petersburg, FL.Online Links:
Nancy T. DeWitt assisted in the bathymetric surveys and data processing. L. Thornton processed the historical data and provided GIS support.
727 803-8747 x 3036 (voice)
727 803-2030 (FAX)
mhansen@usgs.gov
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 had not been systematically mapped in nearly 100 years, and some shallow areas of the bay have never been mapped. An accurate, modern bathymetric survey provides a baseline for assessing future sedimentation rates in the Bay, and a foundation for developing a sediment budget. Due to the complexity of the Bay and age of existing data, a current bathymetric grid (digitally derived from the survey) is critical for numerical models.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. Application of these models is complicated due to the complex seafloor topography (basin/mudbank morphology) of the Bay. The only complete topography data set of the Bay is 100 years old. Consequently, an accurate, modern seafloor bathymetry map of the Bay is critical for numerical modeling research. A modern bathymetry data set will also permit a comparison to historical data in order to help access sedimentation rates within the Bay.
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.
Person who carried out this activity:
727-803-8747 ext.3036 (voice)
727-803-2032 (FAX)
mhansen@usgs.gov
Hansen, Mark DeWitt, Nancy T., 2000, 1890 and 1990 Bathymetry of Florida Bay: USGS Open-File Report OFR 00-347, U.S. Geological Survey, St. Petersburg, FL.Online Links:
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.
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.
not available
not applicable
Are there legal restrictions on access or use of the data?
- Access_Constraints: none
- Use_Constraints:
- The U.S. Geological Survey must be referenced as the originator of the data from this project in any future products or research derived from these data.
727-803-8747 ext.3036 (voice)
727-803-2032 (FAX)
mhansen@usgs.gov
1890 and 1990 trackline data
The data have no explicit or implied guarantees.
| Data format: | ASCII |
|---|---|
| Network links: |
<http://sofia.usgs.gov/publications/ofr/00-347/> |
727 803-8747 ext 3028 (voice)
727 803-2030 (FAX)
sofia-metadata@usgs.gov
U.S. Department of the Interior, U.S. Geological Survey, Center for
Coastal Geology
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