Survey lines along which swath backscatter data were collected south of Martha's Vineyard and north of Nantucket by the U.S. Geological Survey offshore of Massachusetts in 2013 (2013-003-FA_BackscatterTracklines, Esri Polyline Shapefile, Geographic, WGS84)

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Frequently anticipated questions:

What does this data set describe?

Title:
Survey lines along which swath backscatter data were collected south of Martha's Vineyard and north of Nantucket by the U.S. Geological Survey offshore of Massachusetts in 2013 (2013-003-FA_BackscatterTracklines, Esri Polyline Shapefile, Geographic, WGS84)
Abstract:
These data were collected under a cooperative agreement between 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 5 to 30 meters (m) 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 geophysical data were collected during a survey in 2013 during USGS Field Activity 2013-003-FA (http://cmgds.marine.usgs.gov/fan_info.php?fa=2013-003-FA) and cover approximately 185 square kilometers of the inner continental shelf.
  1. How might this data set be cited?
    U.S. Geological Survey, 2016, Survey lines along which swath backscatter data were collected south of Martha's Vineyard and north of Nantucket by the U.S. Geological Survey offshore of Massachusetts in 2013 (2013-003-FA_BackscatterTracklines, Esri Polyline Shapefile, Geographic, WGS84): Open-File Report 2016-1168, 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.

    Ackerman, Seth D., Brothers, Laura L., Foster, David S., Andrews, Brian D., Baldwin, Wayne E., and Schwab, William C., 2016, High-Resolution Geophysical Data From the Inner Continental Shelf: South of Martha's Vineyard and North of Nantucket, Massachusetts: Open-File Report 2016-1168, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.805409
    East_Bounding_Coordinate: -70.034621
    North_Bounding_Coordinate: 41.388894
    South_Bounding_Coordinate: 41.196104
  3. What does it look like?
    http://pubs.usgs.gov/of/2016/1168/GIS_catalog/browse_img/big/2013-003-FA_BackscatterTracklines.jpg (JPEG)
    Swath backscatter trackline navigation for south of Martha's Vineyard and north of Nantucket, Massachusetts
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 22-May-2013
    Ending_Date: 11-Jun-2013
    Currentness_Reference:
    ground condition of survey dates: 20130522-20130611; see Completeness_Report for more information
  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 (251)
    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 WGS_1984.
      The ellipsoid used is WGS 84.
      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?
    2013-003-FA_BackscatterTracklines
    Trackline for swath backscatter sonar system (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
    Survey line/file name; generally in the format l###f@-CH12 where ### is the name of the trackline along which swath bathymetric data was collected, @ is the file iteration (indicates the survey line was split into multiple files during acquisition) and CH12 indicated that channels 1 and 2 were imported. For example: survey line 179 was interrupted 30 minutes into the line, the ship circled around to the location where surveying was paused; there are 2 tracklines for line 179 "l179f1-CH12" and "l179f2-CH12". (Source: USGS) String up to 18 characters
    Yr_JD_str
    Year and Julian day of the start of data collection for a specific survey line where Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. For example: the Yr_JD_str field for l100f1_sxp is "2013-154" (Source: USGS) 8 character string
    JD_UTC_str
    Julian day and time in UTC of the start of data collection for a specific survey line where Julian day is the integer number representing the interval of time in days since January 1 of the year of collection and UTC time is time represented in the format "hh:mm:ss". For example: the JD_UTC_str field for l100f1_sxp is "154:05:07:43" (Source: USGS) 12 character string
    Yr_JD_end
    Year and Julian day of the end of data collection for a specific survey line where Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. For example: the Yr_JD_end field for l100f1_sxp is "2013-154" (Source: USGS) 8 character string
    JD_UTC_end
    Julian day and time in UTC of the end of data collection for a specific survey line where Julian day is the integer number representing the interval of time in days since January 1 of the year of collection and UTC time is time represented in the format "hh:mm:ss". For example: the JD_UTC_end field for l100f1_sxp is "154:06:07:22" (Source: USGS) 12 character string
    SurveyID
    WHCMSC field activity identifier in the new style (e.g. "2013-003-FA" where 2013 is the survey year, 003 is survey number of that year, and FA is Field Activity); Note the old style of this would be represented as "13003" (Source: USGS) 11 character string
    VehicleID
    Name of the survey vessel used for data collection (Source: USGS) 21 character string
    DeviceID
    Name of the sonar device used to collect swath backscatter data (Source: USGS) 16 character string
    Length_km
    Length of the swath backscatter survey line in kilometers (UTM Zone 19N, WGS84) (Source: USGS)
    Range of values
    Minimum:0.67
    Maximum:22.30

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?
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov

Why was the data set created?

The backscatter data collected along these tracklines were used to define the seafloor morphology as part of the Massachusetts Seafloor Mapping Project. This dataset contains approximately 1840 linear kilometers of trackline navigation for interferometric sonar (Systems Engineering and Assessment Ltd. SWATHPlus-M) backscatter data collected by the U.S. Geological Survey during USGS survey 2013-003-FA in 2013 offshore of Massachusetts, south of Martha's Vineyard and north of Nantucket.

How was the data set created?

  1. From what previous works were the data drawn?
    raw data (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, raw backscatter data.

    Type_of_Source_Media: disc
    Source_Contribution:
    This trackline navigation dataset document the ship tracks along which swath-backscatter data was collected by the USGS (with a 234 kHz Systems Engineering and Assessment Ltd. (SEA) SWATHplus interferometric sonar mounted on the M/V Scarlett Isabella). Data were acquired during May and June 2013. USGS Configuration: Survey: Survey lines were run at an average speed of 5 knots and were generally spaced 100 m apart to obtain overlapping swaths of data and full seafloor coverage. Sonar: The SEA SWATHplus-M operates at a frequency of 234 kHz and a variable range (increased or decreased manually depending on water depth). The system was operated with a transmit power: 80 percent, a transmit length: 43 cycles, 4096 samples per channel, ping rate of 15 per second. Additional sonar configuration information can be found in the metadata for the backscatter mosaic (2013-003-FA_Backscatter1m.tif) included with this report (USGS Open-File Report 2016-XXXX, High-Resolution Geophysical Data From the Inner Continental Shelf: South of Martha's Vineyard and North of Nantucket, Massachusetts. at http://pubs.usgs.gov/of/2016/1168/ofr2016-1168-data_catalog.html).
  2. How were the data generated, processed, and modified?
    Date: 2013 (process 1 of 8)
    Raw data: Survey navigation information is stored within each raw (sxr) data file. Raw SWATHPlus bathymetric sonar files (sxr) were acquired using SEA SWATHPlus Swath Processor (ver. 3.07.17). This process step and all subsequent process steps were performed by the same person - Seth Ackerman. Person who carried out this activity:
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700x2315 (voice)
    (508) 457-2310 (FAX)
    sackerman@usgs.gov
    Data sources used in this process:
    • raw data
    Date: 2013 (process 2 of 8)
    SonarWiz Import: A new Chesapeake Technology SonarWiz project (ver. 5.06.0018) was created with projection information set to Universal Transverse Mercator (UTM) Zone 19, WGS84. Each SWATHPlus raw file (SXR) was imported to the new SonarWiz project using the Import -> Sidescan Files Wizard. Generally the default options were used; being sure to select the option for "channels 1 and 2" and the "Navigation is stored in MCOM (F-180) binary packets" option under "File Type Specific Options" (SEA SwathPlus).
    Date: Oct-2015 (process 3 of 8)
    SonarWiz Processing: Backscatter data were processed in SonarWiz (ver. 5 and 6). After processing was complete, navigation was exported from SonarWiz (ver. 6.01.0032) as a CSV (Comma Separated Value) text file by selecting TOOLS and EXTRACT CSF (Chesapeake Sonar File) NAVIGATION TO TEXT FILE.
    Date: Feb-2016 (process 4 of 8)
    Python and shell scripts were used to reformat the navigation text files and add them to a SQLite database (version 2.6.0) that was geospatially extended using SpatiaLite (version 4.2.0_1). The processing flow for this step follows: A. A Python script (pyReformatSidescanNav.py) was used to read and reformat CSV navigation files. The script reformatted each record to include the Julian Day (JD) with year and time, and it added fields for the survey line name, field activity number (2013-003-FA), survey vessel (M/V Scarlett Isabella) and the device used (SWATHplus 234(M)). B. A Python script (pySQLBSidescanNav.py) ran on each reformatted CSV file, parsing the file from each record and adding points to the SQLite database (which is created if it does not already exist). The pySQLSidescanNav script creates both point and trackline navigation for each survey line. This process populates attribute fields for the survey line ('LineName'), Year and Julian day ('Year_JD_init') survey line started, Julian day and UTC time ('JD_UTC_init') survey line started, Year and Julian day ('Year_JD_end') survey line ended, Julian day and UTC time ('JD_UTC_end') survey line ended, survey ID ('SurveyID'), survey vessel name ('VehicleID'), device used to collect the data ('DeviceID') and length field ('Length_km'). C. When all of the survey lines have been processed into the SQLite database, a polyline shapefile is exported from the database using spatialite_tools (ver. 4.1.1). Steps A and B were both run within a shell script called sonarwiznavconv.
    Date: Feb-2016 (process 5 of 8)
    XTools Pro (version 12.0) for ArcGIS desktop was used (Table Operations - Table Restructure) to rename long attribute headings in the polyline shapefile's attribute table. Table attributes for the survey line ('LineName'), Year and Julian day ('Yr_JD_str') survey line started, Julian day and UTC time ('JD_UTC_str') survey line started, Year and Julian day ('Yr_JD_end') survey line ended, Julian day and UTC time ('JD_UTC_end') survey line ended, survey ID ('SurveyID'), survey vessel name ('VehicleID'), device used to collect the data ('DeviceID') and length field ('Length_km') of each line were already populated but renamed if necessary.
    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?
    Denny, J.F., Danforth, W.W., Foster, D.S., and Sherwood, C.R., 2009, Geophysical Data Collected off the South Shore of Martha's Vineyard, Massachusetts: Open-File Report 2008-1288, 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?
  2. How accurate are the geographic locations?
    USGS Field Activity 2013-003-FA: Navigation was acquired with a Coda Octopus F185R Real-time Kinematic Global Positioning System (RTK-GPS); which is accurate to less than 1 meter (typically on the order of centimeters), horizontally. The SWATHPlus-M transducers were mounted on a rigid pole, approximately 2.17 m below the water line, along the port side of the M/V Scarlett Isabella. The RTK-GPS antenna was located on the same pole approximately 4.6 m above the sea surface. These offsets were corrected within the SWATHPlus acquisition software.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This dataset includes all of the swath-backscatter trackline navigation that was processed for USGS field activity 2013-003-FA. On a case by case basis, some of the swath-backscatter data may not have been processed and therefore no trackline was created (e.g. if a line was stopped for various reasons and a new line was restarted covering the same area of the original survey line or if a line was split during processing and a section of the line was not used or processed). Line L1f1 was split due to navigation errors and issues with staying on the survey line. The line was restarted as L1f2, and the split off section at the end of line L1f1 was discarded. Line L59f1 was split so that data collected after the end of the line, during a turn and transit to the next survey line, could be discarded. L43f1 was split into L43f1-CH12 and L43f1-CH12-SPL000, and both were processed and included in the backscatter mosaic. Line L212f1 was split where the vessel veered offline to collect a sound speed cast, and the split off section was discarded. This shapefile includes trackline navigation from all processed swath-backscatter data; only quality sonar data along the main survey lines were included in the final backscatter mosaic (2013-003-FA_Backscatter1m.tif) found in this report. Excessively noisy or poor quality data were not included in the final mosaic. Data from some survey lines were omitted where they overlapped with equal or better quality data from adjacent lines. Data along tie and transit lines were generally not included in the final mosaic either. An approximately 24 square kilometer area offshore of Edgartown Great Pond (south of Martha's Vineyard, MA) was not surveyed because it was surveyed in 2007 using the same system as part of a separate project to study the area around Woods Hole Oceanographic Institution (WHOI) Martha's Vineyard Coastal Observatory (MVCO), see USGS Open File Report 2008-1288 for more information http://pubs.usgs.gov/of/2008/1288/. The only data from the SWATHplus system processed and published from the 2007 survey was the swath bathymetry; backscatter data from 2007 survey was from a Klein 3000 dual-frequency sidescan-sonar (L3-Klein Associates). Time gaps occurred during this field activity where no surveying was done due to bad weather, rough seas and stops in port for crew changes. Planned surveying was paused and no main survey line data were collected during these times: 
    JD143 15:20 - JD146 20:06 (no data were collected on JD144 or JD145)
JD149 15:40 - JD151 18:59 (no data were collected on JD150)
JD153 00:01 - JD153 14:32
JD155 18:16 - JD156 02:06
JD158 06:12 - JD160 19:15 (no data were collected on JD159)
  5. How consistent are the relationships among the observations, including topology?
    Much of the excessively noisy or poor quality data were removed during processing. The backscatter trackline for L1F1 deviates slightly from the bathymetry trackline. The backscatter trackline for L1F1 exhibits the true course-over-ground, while the bathymetry trackline is smoothed from data processing where swath data were edited.

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)
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2013-003-FA backscatter navigation tracklines from south of Martha's Vineyard and north of Nantucket. The zip file contains a shapefile (2013-003-FA_BackscatterTracklines.shp) and metadata files in three standard formats.
  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 data available in Esri shapefile format. The zip file also contains associated metadata. The user must have software to read and process the data file. 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: 18-Mar-2024
Metadata author:
Seth Ackerman
U.S. Geological Survey
Geologist
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 x2315 (voice)
508-457-2310 (FAX)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)
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/ofr2016-1168/2013-003-FA_BackscatterTracklines_meta.faq.html>
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