Backscatter Imagery from Sidescan Sonar 5 meter/pixel of Boston Harbor and Approaches (bh_5mBS.tif)

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Frequently anticipated questions:


What does this data set describe?

Title:
Backscatter Imagery from Sidescan Sonar 5 meter/pixel of Boston Harbor and Approaches (bh_5mBS.tif)
Abstract:
These data are high-resolution acoustic backscatter measurements of the seafloor from Boston Harbor and the harbor approaches, Massachusetts. Approximately 170 km² of sidescan sonar data were collected by the National Oceanic and Atmospheric Administration (NOAA) Ship Whiting in 2000 and 2001 and reprocessed by the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS).
  1. How might this data set be cited?
    Ackerman, Seth, 2006, Backscatter Imagery from Sidescan Sonar 5 meter/pixel of Boston Harbor and Approaches (bh_5mBS.tif): Open-File Report 2006-1008, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Ackerman, S.D., Butman, B., Barnhardt, W.A., Danforth, W.W., and Crocker, J.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, Reston, VA.

    Online Links:

    Other_Citation_Details: 1 DVD-ROM
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.066756
    East_Bounding_Coordinate: -70.806420
    North_Bounding_Coordinate: 42.438013
    South_Bounding_Coordinate: 42.253690
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 19-Sep-2000
    Ending_Date: 30-Oct-2001
    Currentness_Reference:
    ground condition
  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 4000 x 4200 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 5.000000
      Ordinates (y-coordinates) are specified to the nearest 5.000000
      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?
    Band_1
    Information unavailable from original metadata. (Source: Information unavailable from original metadata.)
    ObjectID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Seth Ackerman
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us

Why was the data set created?

These data were collected by the National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) branch as part of their periodic hydrographic mapping for nautical charting. The raw datasets were provided by NOAA to the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS) in Woods Hole, MA as part of a cooperative agreement to provide high resolution bathymetry and backscatter intensity maps and digital GIS information for resource management, scientific research, industry and the public.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata. (source 1 of 1)
    (assumed), NOAA, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: External Hard Drive
    Source_Contribution:
    The original geophysical data for this project were collected during four hydrographic surveys conducted by NOAA NOS in 2000 and 2001 on the NOAA Ship Whiting and its launches 1005/1014. Multibeam bathymetric data were acquired with a Reson SeaBat 8101 and sidescan sonar backscatter data were acquired with Edgetech model 272-T (100 kHz) or the Klein T-5500 (455 kHz) sonar systems.
  2. How were the data generated, processed, and modified?
    Date: unknown (process 1 of 11)
    Sidescan data were acquired by NOAA NOS with the Edgetech model 272-T (100 kHz) or the Klein T-5500 (455 kHz) sidescan sonar systems. Equipment was either hull mounted or towed. Range, layback, gain and other acquisition parameters varied and were adjusted accordingly in the acquisition software. Raw .xtf sonar files were transferred from NOAA NOS to the USGS/CZM.
    Date: unknown (process 2 of 11)
    The raw sidescan-sonar data were processed using XSonar/ShowImage software. The processing steps included demultiplexing the raw sidescan data using a median filtering routine to suppress speckle noise, a file check of navigation points to delete repeated fixes or other logging errors, correct for slant-range distortion, signal attenuation, and dropped sonar lines (Danforth, W.W., 1997, Xsonar/ShowImage: A complete system for rapid sidescan-sonar processing and display: U.S. Geological Survey Open File Report 97-686, 77 p.). Person who carried out this activity:
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    c/o U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us
    Date: unknown (process 3 of 11)
    PCI Geomatics is a commercially available software package used to digitally mosaic sidescan-sonar records. The geographically oriented raster imagery is imported as individual line files. Adjacent sidescan-sonar records are compared to establish ground control points at common target locations. This helps to correct for navigational errors and potential feature offset due to undefined layback of the tow vehicle. A stencil line is drawn around an individual swath record to crop and paste it on an adjacent swath. This procedure is repeated for each sidescan-sonar line swath to form a composite digital mosaic of the area. Person who carried out this activity:
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    c/o U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us
    Date: unknown (process 4 of 11)
    A linear stretch was applied in to the sidescan sonar image to make adjacent areas mapped with different sonar systems internally consistent. The processed data from a given system, in many cases, were constrained to a limited range of backscatter intensity values. Adjustments were made to the greyscale imagery to tone-match and keep each survey internally consistent. The process described above for mosaicking in PCI was then repeated of each area mapped by a specific system and the patchwork of sidescan sonar images were combined into a composite image for the entire study area. Person who carried out this activity:
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    c/o U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us
    Date: unknown (process 5 of 11)
    A linear contrast stretch was applied to the final image. The lightest and darkest pixel levels were clipped to the upper and lower limits of the image's histogram. This redistributed the remaining levels between 0-255. The redistribution increases the tonal range of the image, improving the visual contrast between areas that originally had small tonal differences. Person who carried out this activity:
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    c/o U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us
    Date: unknown (process 6 of 11)
    In ArcCatalog 9.0, Spatial Analyst -> Aggregate was use to desample the cell size of the GeoTIFF image. Input raster: bh_1mbs.tif, Output raster: bh_5mbs.tif, Cell Factor: 5, Aggregate technique: median. Person who carried out this activity:
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    c/o U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us
    Date: 01-Feb-2017 (process 7 of 11)
    Edits to the metadata were made to fix any errors that MP v 2.9.36 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.). The source information was incomplete and had to be modified to meet the standard. An invalid link was removed from the distribution section. 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 Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 29-Jan-2018 (process 8 of 11)
    An error was fixed in one of the originator names. 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: 20-Jul-2018 (process 9 of 11)
    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 10 of 11)
    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 11 of 11)
    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?

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

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    All of the NOAA survey vessels were equipped with Trimble DSM212L Differential Global Positioning System (DGPS) receivers. Launch 1005, which collected all of the multibeam bathymetry, was also equipped with a TSS POS/MV Model 320 (Position and Orientation System for Marine Vessels). Standard bathymetric processing, including tide corrections, soundings accuracy, and quality control were done by the NOAA Office of Coast Survey.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Information unavailable from original metadata.
  5. How consistent are the relationships among the observations, including topology?
    These data have not been quantitatively compared to previous hydrographic data, although they generally agree with qualitative comparison of published NOAA charts.

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:
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)
    Seth Ackerman
    Massachusetts Office of Coastal Zone Management
    Geologist
    c/o U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    seth.ackerman@state.ma.us
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    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.
  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 image is available as a GeoTIFF image with an accompanying world file. To utilize this data, the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image.

Who wrote the metadata?

Dates:
Last modified: 16-Nov-2021
Metadata author:
Seth Ackerman
Massachusetts Office of Coastal Zone Management
Geologist
c/o U.S. Geological Survey
Woods Hole, MA
USA

508-548-8700 x2315 (voice)
508-457-2310 (FAX)
sackerman@usgs.gov
Contact_Instructions:
The metadata contact email address is updated with a current email address.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2006-1008/bh_5mbs.faq.html>
Generated by mp version 2.9.50 on Tue Nov 16 10:06:32 2021