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 (VS_BACKSCATTER_1m.TIF, GeoTIFF image, UTM Zone 19N WGS84 ).

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Frequently anticipated questions:


What does this data set describe?

Title:
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 (VS_BACKSCATTER_1m.TIF, GeoTIFF image, UTM Zone 19N WGS84 ).
Abstract:
These data were collected under a cooperative agreement with the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center (WHSC). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of sea-floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. The project is focused on the inshore waters of coastal Massachusetts, primarily in water depths of 3-30 meters deep. Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports (http://woodshole.er.usgs.gov/project-pages/coastal_mass/). The data collected in the study area located in Vineyard Sound Massachusetts includes high-resolution geophysics (bathymetry, backscatter intensity, and seismic reflection). The data were collected during three separate surveys conducted between 2009 and 2011and cover approximately 340 square kilometers of the inner continental shelf. 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
  1. How might this data set be cited?
    U.S. Geological Survey, 2012, 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 (VS_BACKSCATTER_1m.TIF, 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.

    Online Links:

    This is part of the following larger work.

    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, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.041516
    East_Bounding_Coordinate: -70.424350
    North_Bounding_Coordinate: 41.545470
    South_Bounding_Coordinate: 41.261683
  3. What does it look like?
    http://pubs.usgs.gov/of/2012/1006/GIS/browse_jpg/vs_backscatter_1m.jpg (JPEG)
    gray scale image of sidescan-sonar mosaic
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 02-Jun-2009
    Ending_Date: 17-May-2011
    Currentness_Reference:
    ground condition of individual surveys on the following dates: 2009062-20090603; 20100521-20100604; 20110507-20110509; 20110514-20110517
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: remote-sensing image
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 30500 x 51000 x 1, type Pixel
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 19
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -69.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      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.
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    There are no attributes associated with a GeoTIFF image. Image pixel values contain acoustic-reflectivity values normalized to an 8-bit data range (1-254) with the data range 1-254. Low-backscatter is represented by dark tones (low values) and high-backscatter is represented by bright tones (high values).
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov

Why was the data set created?

The data are used to interpret seafloor composition and regional geology.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata. (source 1 of 1)
    U.S. Geological Survey, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: disc
    Source_Contribution:
    Data acquisition at sea: Sidescan sonar data were collected using a Klein 3000 dual frequency (132/445 kHz) sidescan sonar towed from the M/V Megan T. Miller (2009-002-FA and 2010-004-FA) and the M/V Scarlett Isabella (2011-004-FA). During each survey the sonar was towed from a stern A-frame, and towfish layback values were determined using a cable counter and automatically adjusted as the layback parameter in the Klein SonarPro acquisition software (versions 10.0 and 11.0). Data were acquired along tracklines spaced 100 m apart at a speed of approximately 5 knots. A range of 75-100 meters (150-200 meter swath) was used to collect the data and ensure overlap with adjacent lines. Survey specific details are listed below: 2009-002-FA SonarPro version was 10.0, navigation was recorded from the antenna on the aft end of the acquisition van into the Ashtech BRG2 receiver (DGPS), and sheave offsets were x= -2.0m, y = -8.35m, z = +2.0m. During 2010-004-FA: SonarPro version was 11.0, navigation was recorded from the center antenna on the SWATHplus pole into the Novatel receiver (RTK), and sheave offsets were x = -4.1m, y = -14.94m, z = -1.33m. During 2011-004-FA: SonarPro version was 11.0, navigation was recorded from the antenna on the forward end of the acquisition van into the Ashtech BRG2 receiver (DGPS), and sheave offsets were x = +4.31m, y = -9.18m, and z = 0.0m.
  2. How were the data generated, processed, and modified?
    Date: 2011 (process 1 of 8)
    Step 1. XSonar/ShowImage (version: 2.0) processing (Danforth 1997) The raw sidescan sonar data in eXtended Triton Format (XTF) was converted to a XSonar format using the parameters described below: 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. Processing occurred in 2009, 2010, and 2011. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 2011 (process 2 of 8)
    Step 2. XSonar to TIFF Conversion: Each *.ras file was converted to a raw raster file (*.raw) in XSonar at a resolution of 1-m per pixel. The 80-byte header for each *ras raster file was removed and the images were converted to a raster (.raw) file with the command: dd if=filename.ras of=filename.raw bs=80 skip=1. The resulting rasters (.raw) were converted to a TIFF using Adobe Photoshop (ver. 10.0.1). Processing occurred in 2009, 2010, and 2011. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 2011 (process 3 of 8)
    Step 3. A PCI Geomatica (version 10.1) project was created for each subarea of the Vineyard Sound survey area. The working mosaics were imported into PCI Geomatica to be digitally mosaicked together using PCI's OrthoEngine and procedures described in Paskevich 1996. The mosaicking process produces an enhanced, geographically correct, sidescan-sonar mosaic with 1 meter/pixel resolution. The Vineyard Sound survey area was divided into a three subareas to maintain reasonable file sizes. The subareas were then mosaicked together into a composite backscatter image for the entire survey area. The composite mosaic was exported as a GeoTIFF image. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 2012 (process 4 of 8)
    Step 4. Using PCI Geomatica (ver. 10.1) , all of the NODATA areas were selected and made to have a single NODATA value, such that all NODATA in the final mosaic will have a pixel value of 255. All backscatter data within the survey area have a value of less than 255, although some small data gaps (NODATA) do occur within the survey area. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 25-May-2016 (process 5 of 8)
    Edits to the metadata were made to fix any errors that MP v 2.9.32 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Fixed a link to the project page in the abstract. The link to the data in the Identification_Information section had to be fixed. The link to the data in the Distribution_Information section had to be fixed. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 6 of 8)
    USGS Thesaurus keywords added to the keyword section. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 18-Nov-2019 (process 7 of 8)
    Crossref DOI link was added as the first link in the metadata. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 08-Sep-2020 (process 8 of 8)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    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, Reston, VA.

    Online Links:


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    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).
  2. How accurate are the geographic locations?
    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.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    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.
  5. How consistent are the relationships among the observations, including topology?
    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.

How can someone get a copy of the data set?

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.
  1. Who distributes the data set? (Distributor 1 of 1)
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    bandrews@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    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.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    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.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
Brian Andrews
U.S. Geological Survey
Geographer
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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