U.S. Geological Survey, 2007, STG2MBath - 2 meter ArcRaster Grid of Swath Bathymetry of St. George Sound, Florida: Open-File Report 2006-1381, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.This is part of the following larger work.Online Links:
Twichell, David C. , Andrews, Brian D. , Edmiston, H. Lee , and Stevenson, William R. , 2007, Geophysical Mapping of oyster habitats in a shallow estuary; Apalachicola Bay, Florida: Open-File Report 2006-1381, U.S. Geological Survey, Woods Hole Science Center, Woods Hole, Massachusetts.Online Links:
This is a Raster data set. It contains the following raster data types:
Planar coordinates are encoded using row and column
Abscissae (x-coordinates) are specified to the nearest 2.000267
Ordinates (y-coordinates) are specified to the nearest 2.000267
Planar coordinates are specified in meters
The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS_1984.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257224.
Sequential unique whole numbers that are automatically generated.
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
These data are high-resolution bathymetric soundings of the bottom of St George Sound, Florida. This ArcRaster grid covers approximately 76 square kilometers of portions of St. George Sound between 0m -10.4m deep.
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Person who carried out this activity:
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
These swath bathymetric data were quantitatively compared to NOAA/NOS single-beam bathymetric data from NOAA Survey HO5810 1979. NOAA Single beam data were shallower than USGS by a mean value of 0.55m. No other comparison to NOAA hydrographic data was conducted.
Cross line junction analysis was computed for lines that crossed from 2005 & 2006 surveys. The mean difference between the cross lines is 0.02 m for St. George Sound.
DGPS is assumed to be accurate within 1-2 meters. Standard GPS is assumed accurate within 5-10 meters. 99% of the positional data is DGPS. Unless noted, all GPS/DGPS data is referenced to WGS84 (NAD83). The configuration of the fathometer was as follows: The fathometer on the RAFAEL was mounted on a pole at the bow of the vessel. Offset between the fathometer pole and GPS antenna was measured. No measurements were taken of ship's pitch, yaw, heave, or change in draft due to water and fuel usage. Motion of the fathometer is not measured. Horizontal accuracy of the fathometer is assumed to be within +/- 3 meters.
Ship motion was recorded with a TSS DMS 2-05 Attitude Sensor, mounted on a head above the interferometric Submetrix 2000 Series transducers. Navigation was recorded using Real Time Kinematic Differential Global Positioning System (RTK-DGPS). The interferometric sonar is an angle-measuring system; depth accuracy decreases with increasing horizontal range. The combined angular accuracy of the Submetrix 2000 Series and the TSS DMS 2-05 attitude sensor is documented as 0.1 degrees. Assuming a constant angular accuracy, and using the International Hydrographic Standard (IHO) of a required 0.3 meter accuracy in < 30 meter water depth, all data collected within the survey fall within the IHO accuracy standards. However, vertical accuracy is also directly affected by the accuracy of both the navigation system and tidal measurements. RTK DGPS vertical accuracy is assumed to be 0.2 meters. Tidal elevations were derived from RTK -DGPS heights sent from a survey-specific base station located on St. George Island.
The base station occupied a temporary monument. The x, & y positions were calculated for that location using a 3 day average of 12 hour data sets using the Online Positioning User Service (OPUS, National Geodetic Survey) solution. Tidal elevations were calculated from NOAA Tidal Station #8728690 using the same OPUS solution and then applied to the corrected elevations for the base station at St. George Island. Antenna heights were referenced to Mean Lower Low Water (MLLW) for easier comparison of NOAA nautical charts.
Bathymetric cross lines were collected and used for accuracy assessment but they were not included in the final grids.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- Data are not intended for navigational use.
These data should not be used at resolutions for which it is not intended.
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Downloadable Data
Although this data set has been used by the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
| Data format: | Grid containing swath bathymetric data collected in St. George Sound, Florida in format ESRI Grid (version ArcGIS 9.2) ESRI Grid File Size: 220.392 |
|---|---|
| Network links: |
<http://pubs.usgs.gov/of/2006/1381/GIS/raster/bath/stg2mbath.zip> |
| Media you can order: |
DVD-ROM
(Density 4.75
Gbytes)
(format UDF)
Note: None
|
These data are available as a 32-bit floating point grid in Environmental Systems Research Institute (ESRI) format. To utilize these data, the user must have software capable of importing and viewing an ESRI ArcRaster grid.
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
