More information about the individual USGS surveys conducted as part of the Vineyard Sound project can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpage:
2009-002-FA: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2009-002-FA>
2010-004-FA: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-004-FA>
2011-004-FA: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-004-FA>
U.S. Geological Survey, 2012, VS_BACKSCATTER_1m.TIF: One meter acoustic backscatter mosaic of data acquired using a Klein 3000 sidescan sonar offshore of Massachusetts within Vineyard Sound by the U.S. Geological Survey in 2009, 2010, and 2011 (GeoTIFF image, UTM Zone 19N WGS84 ).: Open-File Report 2012-1006, 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:
- <http://pubs.usgs.gov/of/2012/1006/GIS/raster/backscatter/vs_backscatter_1m.zip>
- <http://pubs.usgs.gov/of/2012/1006/appendix.html>
Andrews, Brian D. , Ackerman, Seth D. , Baldwin, Wayne E. , Foster, David S. , and Schwab, William C. , 2012, High-Resolution Geophysical Data From the Inner Continental Shelf at Vineyard Sound, Massachusetts: Open-File Report 2012-1006, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine 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 1.000000
Ordinates (y-coordinates) are specified to the nearest 1.000000
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 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
The data are used to interpret seafloor composition and regional geology.
U.S. Geological Survey.
Setup Option: Navigation= Lat/Lon Navigation Interval= 1 minute
Demultiplexing Range and Filter Options: Across track=4 (pixels) Along track= 3 (pixels) Port/Starboard Normalize = 4095 Port High Pass: 65535 Input= 16 bit Normalize Image= yes.
During the demux step, a digital number value of 10 was used as the altitude Search Strength (DN) for the first bottom return. After demultiplexing, each line file (*.d) was reviewed using ShowImage (ver. 1.0) to ensure that the bottom picks were correct and a new bottom was digitized if required.
Next, each file was merged with the navigation created in the demux step and corrected for slant range (*.ds) and beam pattern corrections using the following parameters:
Number of lines= 150 Ping overlap=45 Max beam angle= 90 Response angle=55 Data normalization (0-255)=1 Port/Stbd Tone Adjustment= "on" and "Normal"
The navigation for the final line file (*.dsb) was reviewed using the "Navigation" option in the main Xsonar window. Duplicate points are deleted and navigation is remerged into the ds file if required.
The final step in Xsonar produces separate raster files at 1.0 meter resolution in UTM Zone 19 coordinates for even and odd line files Mosaic boundaries were defined within the survey trackline planning scheme such that the sonar images mapped in XSonar would have the same line orientation and keep the working mosaics to a manageable file size.
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
Danforth, William W. , 1997, XSonar/ShowImage: A complete system for rapid sidescan-sonar processing and display.: Open-File Report 97-686, U.S. Geological Survey, Woods Hole Science Center, Woods Hole, MA.
Paskevich, Valerie, 1996, MAPIT: An improved method for mapping digital sidescan sonar data using the Woods Hole Image Processing System (WHIPS) Software: Open-File Report 96-281, U.S. Geological Survey, Woods Hole Science Center, Woods Hole, MA.
Image pixel values contain acoustic reflectivity values normalized to an 8-bit data range (0-255). Low-backscatter is represented by dark tones (low values) and high-backscatter is represented by bright tones (high values).
Field activity 2009-002-FA: The Klein 3000 was towed from the stern A-frame of the M/V Megan T. Miller. Differential GPS (DGPS) position data were provided by the Ashtech BRG2 receiver and recorded to the raw data files (XTF) via SonarPro (version 10.0) on the sonar acquisition computer. The GPS antenna was mounted on the aft end of the acquisition lab van. All GPS data during this survey was referenced to the WGS84 horizontal datum. The horizontal offsets between the GPS antenna and the sheave on the A-frame were measured prior to the survey (x: -2.0m; y:-8.35m; z:+2m). Additional layback position, accounting for the linear distance between the sheave on the A-frame and the towed sonar system were measured by a 3PS digital block cable counter on the winch that was used to deploy the sidescan-sonar towfish. All of the horizontal offsets were directly applied into the acquisition software so the navigation recorded in the XTF data reflect the position including the layback offset. The layback calculations do not account for fish motion behind the vessel, which is caused by sea state and vessel speed-induced changes in the angle and scope of the tow cable. DGPS positional accuracy is estimated to be within 3-5 m; Wide Area Augmentation System enable DGPS is estimated to be within less than 3 m. Considering the additional fish motion and cable movement, a conservative estimate of positional accuracy for this dataset is estimated to be within 10 m.
Field activity 2010-004-FA: The Klein 3000 was towed from the stern A-frame of the M/V Megan T. Miller. Real-Time Kinematic (RTK) GPS position data were provided by the Novatel DL-V3 receiver and recorded to the raw data files (XTF) via SonarPro (version 11.0) on the sonar acquisition computer. The GPS antenna was mounted on the top of the SWATHplus (interferometric bathymetry) transducer pole, midship on the starboard side (the middle of the 3 bathymetry system antennas). On a few brief occasions the RTK-GPS signal was lost and the navigation system fell back to standalone DGPS or GPS mode. In these cases, the lower quality positions were used and no corrections were made for RTK navigation gaps. All GPS data during this survey were referenced to the WGS84 horizontal datum. The horizontal offsets between the GPS antenna and the sheave on the A-frame were measured prior to the survey (x:-4.1m; y:-14.94m; z:-1.33m). Additional layback position, accounting for the linear distance between the sheave on the A-frame and the towed sonar system were measured by a 3PS digital block cable counter on the winch that was used to deploy the sidescan-sonar towfish. All of the horizontal offsets were directly applied into the acquisition software so the navigation recorded in the XTF data reflect the position including the layback offset. The layback calculations do not account for fish motion behind the vessel, which is caused by sea state and vessel speed induced changes in the angle and scope of the tow cable. RTK positional accuracy is estimated to be within less than 1 m. Taking the additional fish motion, cable movement and RTK-GPS navigation dropouts into account, a conservative estimate of positional accuracy for this dataset is estimated to be within 10 m.
Field activity 2011-004-FA: The Klein 3000 was towed from the stern A-frame of the M/V Scarlett Isabella. Differential GPS (DGPS) position data were provided by the Ashtech BRG2 receiver and recorded to the raw data files (XTF) via SonarPro (version 11.0) on the sonar acquisition computer. The GPS antenna was mounted on the forward end of the acquisition lab van. All GPS data during this survey was referenced to the WGS84 horizontal datum. The horizontal offsets between the GPS antenna and the sheave on the A-frame were measured prior to the survey (x: +4.31m; y:-9.18m; z:0.0m). Additional layback position, accounting for the linear distance between the sheave on the A-frame and the towed sonar system were measured by a 3PS digital block cable counter on the winch that was used to deploy the sidescan-sonar towfish. All of the horizontal offsets were directly applied into the acquisition software so the navigation recorded in the XTF data reflect the position including the layback offset. The layback calculations do not account for fish motion behind the vessel, which is caused by sea state and vessel speed induced changes in the angle and scope of the tow cable. DGPS positional accuracy is estimated to be within 3-5 m; WAAS enable DGPS is estimated to be within less than 3 m. Taking the additional fish motion and cable movement into account, a conservative estimate of positional accuracy for this dataset is estimated to be within 10 m.
This mosaic includes the sidescan backscatter data collected during 2009-002-FA, 2010-004-FA, and 2011-004-FA that are within the Vineyard Sound survey area. Additional data collected during these three surveys in the Buzzards Bay survey area are published USGS Open File Report 2012-1002. This mosaic does not include all acoustic backscatter data collected in the Vineyard Sound survey area. Data collected along transit lines, seismic tie lines, and other lines of poor quality were excluded.
All sidescan-sonar data in this mosaic were collected with a Klein 3000 dual-frequency (132/445 kHz) sidescan-sonar system. Only the 132-kHz data were used to generate the sidescan-sonar mosaic. All data were processed using the same methods.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- These data are not for navigational use. 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)
bandrews@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 file contains a GeoTIFF image and associated world file of sidescan-sonar collected within Vineyard Sound and associated metadata. in format WinZip (version 9.0) Size: 261 Mbytes |
|---|---|
| Network links: |
<http://pubs.usgs.gov/of/2012/1006/GIS/raster/backscatter/vs_backscatter_1m.zip> <http://pubs.usgs.gov/of/2012/1006/appendix.html> |
| Media you can order: |
DVD-ROM
(Density 4.75
Gbytes)
(format UDF)
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This Zip file contains a compressed GeoTIFF image and world file. The user must have software capable of uncompressing the zip file and viewing a GeoTIFF image.
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
