Survey lines along which acoustic backscatter data were acquired using a Klein 3000 sidescan sonar and a SWATHplus interferometric sonar offshore of Massachusetts within the northern Cape Cod Bay survey area (CCB_BackscatterTracklines Esri Shapefile, Geographic, WGS84).

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Frequently anticipated questions:


What does this data set describe?

Title:
Survey lines along which acoustic backscatter data were acquired using a Klein 3000 sidescan sonar and a SWATHplus interferometric sonar offshore of Massachusetts within the northern Cape Cod Bay survey area (CCB_BackscatterTracklines Esri Shapefile, Geographic, 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 (WHCMSC). 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/html/current_map.html). The data collected in the study area located in Northern Cape Cod Bay Massachusetts includes high-resolution geophysics (bathymetry, backscatter intensity, and seismic reflection), and ground validation (sediment samples, video tracklines, and bottom photographs). The data were collected during five separate surveys conducted between 2006 and 2008 and cover 480 square kilometers of the inner continental shelf. 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/
  1. How might this data set be cited?
    U.S. Geological Survey, 2010, Survey lines along which acoustic backscatter data were acquired using a Klein 3000 sidescan sonar and a SWATHplus interferometric sonar offshore of Massachusetts within the northern Cape Cod Bay survey area (CCB_BackscatterTracklines Esri Shapefile, Geographic, WGS84).: 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 part of the following larger work.

    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, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.643112
    East_Bounding_Coordinate: -70.112701
    North_Bounding_Coordinate: 42.093597
    South_Bounding_Coordinate: 41.931839
  3. What does it look like?
    http://pubs.usgs.gov/of/2010/1006/GIS/browse_jpg/CCB_BackscatterTracklines.jpg (JPEG)
    Thumbnail image of backscatter tracklines
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 16-Aug-2006
    Ending_Date: 07-May-2008
    Currentness_Reference:
    ground condition of four separate date ranges - 20060816 to 20060823; 20070429 to 20070503; 20070725 to 20070807; 20080429 to 20080507
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • String (643)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. 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?
    CCB_BackscatterTracklines
    Tracklines for backscatter data collected in the Cape Cod Bay survey area. (Source: USGS)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: ESRI) Coordinates defining the features.
    LINENAME
    Name of sidescan-sonar file recorded along the survey line. This name is assigned by SonarPro acquisition software and is composed of Hypack survey line+ date+time. Where linename = l100f106081514400 l100f1= Hypack survey line, 060815 = year, month, day (2006, August 15), and 14400 = time stamp in UTC of start of line 14 hours, 40 minutes 0 seconds (Source: USGS) Information unavailable from original metadata.
    JD
    Julian Day the data were collected (Source: USGS) Information unavailable from original metadata.
    Survey
    WHCMSC field activity number (Source: USGS) Information unavailable from original metadata.
    Sonar
    Type of Sonar used to collect the backscatter data (Source: USGS) Character string of width 25
    Mosaic
    Identifies the lines used to as source for the final backscatter mosaic. (Source: USGS) Character string of width 10
    Length_KM
    Length of the polyline feature in kilometers (calculated using UTM Zone 19, WGS84). (Source: USGS)
    Range of values
    Minimum:0.0024
    Maximum:9.76
    Units:kilometers (km)

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 purpose of these data is to provide the trackline navigation and filenames of the 3,009 km of acoustic backscatter data acquired using a Klein 3000 sidescan sonar and a SWATHplus interferometric sonar in the northern Cape Cod Bay survey area.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata. (source 1 of 1)
    Information unavailable from original metadata. Assumed to be USGS., unknown, Information unavailable from original metadata..

    Other_Citation_Details:
    This file had a source contribution, but no other source information. This information had to be modified to meet the standard.
    Type_of_Source_Media: Information unavailable from original metadata.
    Source_Contribution:
    Acoustic backscatter data acquisition for field activities 06012 and 07002: The Klein 3000 towfish was deployed from the stern A-frame of the R/V Megan T. Miller. A digital cable counter attached to the winch used to deploy the sidescan-sonar towfish measured changes in the amount of cable extended from the A-frame and updated the "cable out" parameter in SonarPro acquisition software (version 9.6). During survey 07002 The winch used to deploy and retrieve the Klein 3000 towfish was inoperable between Aug 1and 2, 2007. During this time, the acoustic backscatter collected with the 117 kHz SEA SWATHplus interferometric sonar was used to fill the gap in the Klein 3000 backscatter. 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 Acoustic backscatter data acquisition for field activities 07001 and 08002: The Klein 3000 towfish was deployed from a davit on the port side of the R/V Rafael approximately 1 m astern and 0.5 m below the water surface. Swath width was 100 m either side of the vessel (200 m total) for field activities 06012, 07001 and 08002. Swath width for field activity 07002 was increased to 150 m range (300 m total) because tracklines we spaced 150 m apart.
  2. How were the data generated, processed, and modified?
    Date: 2009 (process 1 of 8)
    Navigation was extracted at a 1 minute interval from the raw sidescan sonar data (XTF format) in XSonar (version: 1.1) using the 'demultiplex' function (Danforth and others, 1991). The ASCII navigation from Xsonar was and concatenated for each survey (using shell scripts convertXsonarNav (no version) and Xsonar2ArcNav (no version)) into comma-separated value (CSV) text files with the following attributes: East, North, Julian Day, Line, Lon, Lat. Separate CSV files were generated for each of the four geophysical surveys. 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: 2009 (process 2 of 8)
    In ArcCatalog (version 9.3), the ASCII navigation file in CSV format for each survey was converted to a point feature class using ArcCatalog (version 9.3) by right-clicking on the comma separated text file -- Create Feature Class -- from XY table. {output file: "SurveyName"_k3k_navpts.shp in geographic coordinates]. 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: 2009 (process 3 of 8)
    VAC Extras tool (version: 2.04 FeatConv - Points to Line v2; USGS in-house software) was then used within ArcMap (version 9.3) to convert the point shapefile for each survey into a polyline shapefile. Text attributes for "Survey", "Sonar", and "Mosaic" were added to each shapefile and the values were calculated using the "Field Calculator" in the context menu in ArcCatalog (version 9.3). The backscatter tracklines from each of the four surveys were merged into one shapefile (CCB_BackscatterTracklines.shp) using the "Merge" tool in ArcToolbox (version 9.3). 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: Dec-2009 (process 4 of 8)
    Append tracklines for backscatter data collected with the SWATHplus interferometric sonar. In ArcMap (version 9.3) selected the tracklines (L67f1-L73f1 survey 07002 ) from the CCB_BathTracklines.shp where backscatter was collected with the SWATHplus interferometric sonar was used to fill the gap in the Klein 3000 backscatter and exported to a new shapefile (CCB_SWATHplus_bstracklines.shp). Reformatted shapefile attributes to match the attributes in CCB_BackscatterTracklines.shp and then appended CCB_SWATHplus_bstracklines.shp to CCB_BackscatterTracklines.shp. Using ArcCatalog (version 9.3) added the attribute Length_KM and used the "calculate geometry" context menu to calculate the length in km of each line using the UTM Zone 19N coordinate system. 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
    Data sources used in this process:
    • CCB_BathTracklines.shp (this publication)
    Date: 20-Nov-2015 (process 5 of 8)
    Edits to the metadata were made to fix any errors that MP v 2.9.30 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 format of the time period of content had to be fixed. An online link to the larger work citation had to be fixed. This file had a source contribution, but no other source information. This information had to be modified to meet the standard. 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?
    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, Reston, VA.

    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, Reston, VA.

    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, Reston, VA.

    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, Reston, VA.

    Online Links:

    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, Reston, VA.

    Online Links:


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

  1. How well have the observations been checked?
    All attributes were checked in a consistent manner.
  2. How accurate are the geographic locations?
    Field activities 06012 and 07002: The Klein 3000 towfish was deployed from the stern A-frame of the R/V Megan T. Miller. Real-time kinematic (RTK) GPS navigation data were provided by an Ashtech Z-Extreme receiver (an Ashtech BR2G DGPS was used as a backup system) and recorded to the raw data files (XTF) via the Klein SonarPro (version 9.6 & 10.0) acquisition software. During some portions of the survey, technical difficulties caused the GPS systems to malfunction and lose the "fixed" RTK signal. When this occurred, the navigation system generally defaulted to a "float" RTK or DGPS signal, or the navigation was lost. When possible, surveying was halted until a reliable GPS signal was restored. A digital cable counter attached to the winch used to deploy the sidescan-sonar towfish measured changes in the amount of cable extended from the A-frame and updated the cable out parameter in SonarPro. Using the cable out value and linear offset between the A-frame and the RTK-GPS antenna (mounted mid-ship on the starboard side directly above the SWATHplus transducers), Sonar Pro calculated towfish layback positions in real time and recorded them to the XTF file headers. A conservative estimate of positional accuracy is ± 10 m, but when the navigation system was providing the "fixed" RTK signal, positional accuracy is likely < 1 m. Positional uncertainty arises because 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. Field Activity 07002 SEA SWATHplus backscatter: The winch used to deploy and retrieve the Klein 3000 towfish was inoperable between Aug 1-2, 2007. During this time, the acoustic backscatter collected with the 117 kHz SEA SWATHplus interferometric sonar was used to fill the gap in the Klein 3000 backscatter. 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. Real-time kinematic (RTK) GPS navigation data were provided by an Ashtech Z-Surveyor Extreme receiver (an Ashtech BR2G DGPS was used as a backup navigation system) and recorded to the raw data files (SXR) via the SWATHplus (version 2.07) acquisition software. A conservative estimate of positional accuracy is likely <1 m. Field activities 07001 and 08002: The Klein 3000 towfish was deployed from a davit on the port side aft on the R/V Rafael at a fixed distance that was accounted for during acquisition. Real-time kinematic (RTK) GPS navigation data were provided by an Ashtech Z-Surveyor Extreme receiver and recorded to the raw data files (XTF) via the Klein SonarPro (version 9.6 and 10.0) acquisition software. A conservative estimate of positional accuracy is ± 10 m, but when the navigation system was providing the "fixed" RTK signal, positional accuracy is likely <1 m.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Only the subset of sidescan-sonar trackline navigation data collected during field activities 06012 and 07001 that are within the northern Cape Cod Bay study area between Duxbury Beach and Provincetown have been included in this spatial dataset. This dataset includes all the tracklines collected during field activities 07002 and 08002.
  5. How consistent are the relationships among the observations, including topology?
    Any spurious data points were removed during processing. Duplicate names may exist for the FILENAME attribute because this is made up of data from multiple surveys; however further querying the data by SURVEY attribute will distinguish a unique trackline for each record in this spatial dataset.

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 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?
    • Availability in digital form:
      Data format: Trackline navigation for acoustic backscatter collected within the northern Cape Cod Bay survey area. in format SHP (version ArcGIS 9.3) ESRI polyline shapefile Size: 0.541
      Network links: http://pubs.usgs.gov/of/2010/1006/GIS/shapefile/CCB_BackscatterTracklines.zip
      Media you can order: DVD-ROM (Density 4.75 Gbytes) (format UDF)
    • Cost to order the data: none

  5. What hardware or software do I need in order to use the data set?
    This zip file contains data available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have software capable of uncompressing the WinZip file and displaying the shapefile. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

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)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2010-1006/CCB_BackscatterTracklines.shp.faq.html>
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