More information about the individual USGS surveys conducted as part of the northern Cape Cod Bay project can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpage:
06012: <http://quashnet.er.usgs.gov/data/2006/06012/> 07001: <http://quashnet.er.usgs.gov/data/2007/07001/> 07002: <http://quashnet.er.usgs.gov/data/2007/07002/> 07003: <http://quashnet.er.usgs.gov/data/2007/07003/> 08002: <http://quashnet.er.usgs.gov/data/2008/08002/>
U.S. Geological Survey, 2010, CCB_SWATH_BS_1M: One meter backscatter mosaic acquired by the U.S. Geological Survey with the 117- kHz SEA Ltd. SWATHplus interferometric sonar offshore of Massachusetts within northern Cape Cod Bay (GeoTIFF IMAGE, UTM19 N).: Open-File Report 2010-1006, 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:
- <https://pubs.usgs.gov/of/2010/1006/GIS/raster/backscatter/CCB_Swath_bs_1m.zip>
- <https://pubs.usgs.gov/of/2010/1006/html/appendix1.html>
Andrews, Brian D. , Ackerman, Seth D. , Baldwin, Wayne E. , and Barnhardt, Walter A. , 2010, Geophysical and Sampling Data from the Inner Continental Shelf: Northern Cape Cod Bay, Massachusetts.: Open-File Report 2010-1006, 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:
The map projection used is Transverse Mercator.
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 purpose of this GeoTIFF is to publish the acoustic backscatter of the seafloor acquired with the 117-kHz SWATHplus interferometric sonar offshore of Massachusetts within northern Cape Cod Bay. The Klein 3000 sidescan sonar was primary sonar used to acquire acoustic backscatter during surveys 06012, 07001, 07002, and 08002. However, during August 1-2, 2007 (07002), the winch used to deploy the Klein 3000 sidescan sonar towfish was inoperable. The acoustic backscatter acquired with the 117-kHz SWATHplus interferometric sonar was processed to cover this data gap in the Klein 3000 backscatter data.
Navigation: Navigation was based on a Real-Time Kinematic Global Positioning System (RTK-GPS); the RTK-GPS antenna was mounted directly above the interferometric sonar head. The RTK-corrected GPS signal was sent to the ship from a base station established by the USGS on land. Horizontal (x and y) and vertical (z) offsets between the transducers and motion sensor and antenna and motion sensor were precisely measured and recorded within the SWATHplus acquisition software (SEA Swath Processor (2005)). These offsets are used to establish the motion sensor as the common reference point for data acquisition.
Speed of Sound: Additionally, the depth of the transducers below the water surface was measured and recorded within the SEA Swath Processor acquisition software. This depth was used to derive the speed of sound profile and acoustic ray path based on speed of sound profiles collected within the survey area. Sound-velocity profiles were collected approximately every 2 hours by a hand-casted Applied MicroSystems SV Plus sound velocimeter.
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
Barnhardt, Walter A. , Andrews, Brian D. , and Butman, Bradford, 2006, High-Resolution Mapping of the Inner Continental Shelf: Nahant to Gloucester, Massachusetts: Open-File Report 2005-1293, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.Online Links:
Ackerman, Seth D. , Butman, Bradford, Barnhardt, Walter A. , Danforth, William W. , and Crocker, James M. , 2006, High-Resolution Geologic Mapping of the Inner Continental Shelf: Boston Harbor and Approaches, Massachusetts: Open-File Report 2006-1008, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.Online Links:
Barnhardt, Walter A. , Andrews, Brian D. , Ackerman, Seth D. , Baldwin, Wayne E. , and Hein, Christopher J. , 2009, High-Resolution Geological Mapping of the Inner Continental Shelf: Cape Ann to Salisbury Beach, Massachusetts: Open-File Report 2007-1373, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.Online Links:
Barnhardt, Walter A. , Ackerman, Seth D. , Andrews, Brian D. , and Baldwin, Wayne E. , 2010, Geophysical and Sampling Data from the Inner Continental Shelf: Duxbury to Hull, Massachusetts: Open-File Report 2009-1072, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, Massachusetts.Online Links:
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). No data value is set to 255.
The SWATHplus transducers were mounted on a rigid pole, approximately 2.6 m below the water line, along the starboard side of the R/V Megan T. Miller. Position data were provided by the Z-Surveyor Extreme for real-time kinematic (RTK) navigation (the Ashtech BR2G Differential Global Positioning System (DGPS) was used as a backup navigation system) and recorded to the raw data files (SXR) via SWATHplus (version 2.07) on the acquisition computer. A conservative estimate of positional accuracy is estimated to be 10 m although when the system was recording RTK navigation the positional accuracy may be <1 m as RTK-GPS provides horizontal positional accuracies on the decimeter scale (<http://www.noaa.gov>; <http://www.nos.noaa.gov>; <http://www.ngs.noaa.gov>).
This image does not include all backscatter data collected with the SWATHplus (117 kHz) interferometric sonar. It includes only SWATHplus backscatter data collected during JD 213-214 covering the data gap in the towed Klein sidescan-sonar backscatter data.
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 containing a GeoTIFF backscatter collected by the U.S. Geological Survey with a SEA 117 kHz interferometric sonar offshore of Massachusetts within Northern Cape Cod Bay. in format WinZip (version 9.0) GeoTIFF Size: 16.0 Mb |
|---|---|
| Network links: |
<https://pubs.usgs.gov/of/2010/1006/GIS/raster/backscatter/CCB_Swath_bs_1m.zip> |
| Media you can order: |
DVD-ROM
(Density 4.75
Gbytes)
(format UDF)
|
This Zip file contains a GeoTIFF image and world file. To utilize these data the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image.
508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
