More information about this field activity and the data collected can be found at the Field Activity Web Page (<http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-005-FA>)
U.S. Geological Survey, 2014, FI_BATHYGRD: 10-meter swath bathymetric grid collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (UTM Zone 18N, WGS 84, Esri Binary Grid): Open-File Report 2014-1203, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.This is part of the following larger work.Online Links:
- <https://pubs.usgs.gov/of/2014/1203/GIS/grids/fi_bathy.zip>
- <https://pubs.usgs.gov/of/2014/1203/html/ofr2014-1203-data_catalog.html>
Schwab, William C. , Denny, Jane F. , and Baldwin, Wayne E. , 2014, Maps Showing Bathymetry and Modern Sediment Thickness on the Inner- Continental Shelf Offshore of Fire Island, New York: pre-Hurricane Sandy: Open-File Report 2014-1203, U.S. Geological Survey, Coastal and Marine Geology Program, Reston, VA.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 10.000000
Ordinates (y-coordinates) are specified to the nearest 10.000000
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.
508-548-8700 x 2311 (voice)
508-457-2310 (FAX)
jdenny@usgs.gov
This grid represents approximately 2800 line kilometers of bathymetric data collected in 2011. These data were collected using an interferometric sonar (Systems Engineering and Assessment Ltd. (SEA) SWATHplus-M (234 kHz)) by the U.S. Geological Survey during USGS survey 2011-005-FA. These bathymetric data were used to define the morphology of the sea floor on the inner-continental shelf offshore of Fire Island, New York to help assess environmental change caused by natural processes and human activities.
U.S. Geological Survey, Unpublished Material, Raw Bathymetric Data.
Sonar: Swath-bathymetric and acoustic-backscatter data were acquired with a SEA, Ltd., SWATHplus-M interferometric sonar operating at a frequency of 234 kHz and a variable range (increased or decreased manually depending on water depth). The system was operated with a transmit power: 80 percent, 4096 samples per channel, and a variable range (increased or decreased depending on water depth). The SWATHplus-M was mounted on the port side of the M/V Scarlett Isabella during survey operations. A Coda Octopus F180R Attitude and Positioning system recorded ship motion (heave, pitch, roll, and yaw). These data were transmitted via network connection to the SWATHplus-M acquisition software. The Octopus F180R Inertial Measurement Unit (IMU) was mounted directly above the SEA SWATHplus-M transducers, to minimize lever arm offsets that can lead to positioning errors. The F180R uses two L1 antennas for position and heading accuracy. The antennas are mounted on a rigid horizontal pole, positioned at the top of the sidemount, with a horizontal separation of 1 meter and are offset from the IMU in a forward/aft configuration. The forward offset of the primary antenna from the IMU is 0.5 meters, with no port/starboard offset.
Sound Velocity Profiles: 135 sound velocity profiles were acquired during survey operations at roughly 1 to 3 hour intervals using an Odim MVP30 motion vessel profiler. The MVP30 failed during survey operations. Sound velocity profiles were only collected during JD141 through 143 (lines 1 through 27).
While much effort was devoted to cleaning the data and minimizing survey artifacts, some artifacts may still be seen in the final gridded data including an along track artifact at nadir (the ship track) and at the far edges of a survey line where adjacent swaths overlap. These artifacts are especially noticeable in areas of little local relief.
More information about this field activity and the data collected can be found at the Field Activity Web Page (<http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-005-FA>)
Jane F. Denny performed this and all subsequent process steps.
Person who carried out this activity:
508-548-8700 x 2311 (voice)
508-457-2311 (FAX)
jdenny@usgs.gov
The final surface was exported in ASCII format (xyz - easting, northing, depth) using the Export Wizard, Export BASE Surface to ASCII.
Schwab, William C. , Baldwin, Wayne E. , Hapke, Cheryl J. , Lentz, Erika E. , Gayes, Paul T. , Denny, Jane F. , List, Jeffrey H. , and Warner, John C. , 2013, Geologic Evidence for Onshore Sediment Transport from the Inner Continental Shelf: Fire Island, New York: Journal of Coastal Research Volume 29, Issue 3, pp. 526-544., Coastal Education and Research Foundation, Inc., Florida, USA.Online Links:
Foster, David S. , Swift, Ann B. , and Schwab, William C. , 1999, Stratigraphic Framework Maps of the nearshore area of southern Long Island from Fire Island to Montauk Point, NY: Open-File Report 99-559, U.S. Geological Survey, Reston, VA.Online Links:
Schwab, William C. , Thieler, E. Robert , Denny, Jane F. , Danforth, William W. , and Hill, Jenna C. , 2000, Seafloor sediment distribution off southern Long Island, New York: Open-File Report 00-243, U.S. Geological Survey, Reston, VA.Online Links:
Navigation was acquired with Differential Global Positioning System and Wide Area Augmentation System (DGPS+WAAS), which is accurate to + or - 1 to 2 meters, horizontally. The forward, or primary, Coda Octopus F180R Attitude and Positioning system antenna was used to acquire DGPS data and transmit via a network connection to the SEA SWATHplus data acquisition software. The F180R Attitude and Positioning system uses 2 L1 antennas for position and heading and an Inertial Measurement Unit (IMU) for motion sensing (heave, pitch, roll and yaw). The F180R IMU is mounted directly above the SEA SWATHplus-M transducers on the sidemount. The F180R antennas are mounted at the top of the sidemount offset in a forward/aft configuration. The offsets were applied within the SWATHplus and Coda Octopus F180R acquisition software.
Vertical accuracy of the raw data based on system specifications may approximate 1% of water depth, approximately 0.1 to 0.3 meters within the survey area. However, overall vertical accuracies on the order of 50 cm are assumed based on the following considerations: The Coda Octopus F180R Attitude and Positioning system, used to correct for vessel roll, pitch, heave, and yaw, has a theoretical vertical accuracy of a few mm. Real Time Kinematic (RTK) GPS height corrections, broadcast from a continuously operated reference station (CORS) at Central Islip, New York (station NTCI), were used to reference soundings to the North American Vertical Datum of 1988 (NAVD88) and remove water depth variations caused by tides. USGS field tests (unpublished) using submerged targets suggest that the vertical accuracy of the RTK-GPS tidal correction is less than 30cm. Refraction artifacts were minimized by acquiring sound velocity profiles with an ODIM MVP30 moving vessel profiler. However, the ODIM MVP30 failed half-way through the survey. No sound velocity profiles were collected for the remainder of the survey (lines 48 - 109) and refraction corrections were applied during post-processing. Changes in ship draft due to water and fuel usage were not considered.
Line 1 - 51, 61 - 64, 68 - 87, and 93 - 109 were used to generate the bathymetric grid. Lines 52-60, 65 - 67, and 89 - 92 are tie lines collected orthogonal to the shoreline. Tie lines were used to QA/QC the bathymetric data during data processing, but were not incorporated into the final bathymetric grid.
This grid represents interpolated data; processed to account for gaps that occurred along-track and between adjacent lines.
Are there legal restrictions on access or use of the data?
- Access_Constraints: none
- Use_Constraints:
- These data are NOT to be used for navigation. Mariners should refer to the appropriate nautical chart. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
508-548-8700 x 2311 (voice)
508-457-2311 (FAX)
jdenny@usgs.gov
Downloadable Data
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. 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: | WinZip (version 14.0) file containing the ArcRaster grid of swath bathymetric data collected by the USGS offshore of Fire Island, NY, 2011. This also includes associated metadata. in format AIG (version ArcGIS 9.3) Esri Raster GRID format Size: 10.38 MB |
|---|---|
| Network links: |
<https://pubs.usgs.gov/of/2014/1203/GIS/grids/fi_bathy.zip> <https://pubs.usgs.gov/of/2014/1203/html/ofr2014-1203-data_catalog.html> |
none
These data are available as a ArcInfo 32-bit floating point binary grid in Esri format. The floating point binary grid and associated 'info' folder are stored in one folder 'bathy' that has been compressed using WinZip (ver.14.0) software. To utilize these data, the user must have software capable of uncompressing the zip file and importing and viewing an Esri ArcRaster grid. The zip file also contains associated metadata.
508-548-8700 x 2311 (voice)
508-457-2311 (FAX)
jdenny@usgs.gov
