These data have not been quantitatively compared to previous hydrographic data, although they generally agree with qualitative comparison of published NOAA charts.
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
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.
Source_Information:
Source_Citation:
Citation_Information:
Originator: NOAA (assumed)
Publication_Date: unknown
Title: Information unavailable from original metadata.
Type_of_Source_Media: External Hard Drive
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20000919
Ending_Date: 20011030
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: Information unavailable from original metadata.
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.
Process_Step:
Process_Description:
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.
Process_Date: unknown
Process_Step:
Process_Description:
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.).
Process_Date: unknown
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Seth Ackerman
Contact_Organization: Massachusetts Office of Coastal Zone Management
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: c/o U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2315
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: seth.ackerman@state.ma.us
Process_Step:
Process_Description:
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.
Process_Date: unknown
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Seth Ackerman
Contact_Organization: Massachusetts Office of Coastal Zone Management
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: c/o U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2315
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: seth.ackerman@state.ma.us
Process_Step:
Process_Description:
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.
Process_Date: unknown
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Seth Ackerman
Contact_Organization: Massachusetts Office of Coastal Zone Management
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: c/o U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2315
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: seth.ackerman@state.ma.us
Process_Step:
Process_Description:
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.
Process_Date: unknown
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Seth Ackerman
Contact_Organization: Massachusetts Office of Coastal Zone Management
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: c/o U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2315
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: seth.ackerman@state.ma.us
Process_Step:
Process_Description:
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.
Process_Date: unknown
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Seth Ackerman
Contact_Organization: Massachusetts Office of Coastal Zone Management
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: c/o U.S. Geological Survey
Address: 384 Woods Hole Rd.
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Country: USA
Contact_Voice_Telephone: 508-548-8700 x2315
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: seth.ackerman@state.ma.us
Process_Step:
Process_Description:
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.
Process_Date: 20170201
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Process_Step:
Process_Description: An error was fixed in one of the originator names.
Process_Date: 20180129
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Process_Step:
Process_Description: USGS Thesaurus keywords added to the keyword section.
Process_Date: 20180720
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Process_Step:
Process_Description: Crossref DOI link was added as the first link in the metadata.
Process_Date: 20191118
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Process_Step:
Process_Description:
Added keywords section with USGS persistent identifier as theme keyword.
Process_Date: 20200908
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov