Survey lines along which interferometric sonar (bathymetric and backscatter) data were collected in 2016 by the U.S. Geological Survey off Town Neck Beach in Sandwich, Massachusetts, during field activity 2016-017-FA (polyline shapefile)

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Frequently anticipated questions:

What does this data set describe?

Title:
Survey lines along which interferometric sonar (bathymetric and backscatter) data were collected in 2016 by the U.S. Geological Survey off Town Neck Beach in Sandwich, Massachusetts, during field activity 2016-017-FA (polyline shapefile)
Abstract:
Geophysical and geological survey data were collected off Town Neck Beach in Sandwich, Massachusetts, in May and July 2016. Approximately 130 linear kilometers of subbottom (seismic-reflection) and 234-kilohertz interferometric sonar (bathymetric and backscatter) data were collected along with sediment samples, sea floor photographs, and (or) video at 26 sites within the geophysical survey area. Sediment grab samples were collected at 19 of the 26 sampling sites and video and (or) photographic imagery of the sea floor were taken at all 26 sites. These survey data are used to characterize the sea floor by identifying sediment-texture, seabed morphology, and underlying geologic structure and stratigraphy. Data collected during these 2016 surveys are included in this data release: https://doi.org/10.5066/P9HZHXXV.
More information can be found on the websites for the Woods Hole Coastal and Marine Science Center field activities at https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-017-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-037-FA.
Supplemental_Information:
More information can be found on the WHCMSC Field Activity webpage: https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-017-FA. Data collected during the 2016 survey can be obtained here: https://doi.org/10.5066/P9HZHXXV.
  1. How might this data set be cited?
    U.S. Geological Survey, 2019, Survey lines along which interferometric sonar (bathymetric and backscatter) data were collected in 2016 by the U.S. Geological Survey off Town Neck Beach in Sandwich, Massachusetts, during field activity 2016-017-FA (polyline shapefile): data release DOI:10.5066/P9HZHXXV, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Ackerman, Seth D., Foster, David S., Danforth, William W., and Huntley, Emily C., 2019, High-resolution geophysical and sampling data collected off Town Neck Beach in Sandwich, Massachusetts, 2016: data release DOI:10.5066/P9HZHXXV, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Ackerman S.D., Foster D.S., Danforth W.W., and Huntley, E.C., 2019, High-resolution geophysical and sampling data collected off Town Neck Beach in Sandwich, Massachusetts, 2016: U.S. Geological Survey data release, https://doi.org/10.5066/P9HZHXXV.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.503501
    East_Bounding_Coordinate: -70.456561
    North_Bounding_Coordinate: 41.786541
    South_Bounding_Coordinate: 41.761391
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5c926dc2e4b0938824573d59/?name=2016-017-FA_SWATHplusTracklines_browse.jpg (JPEG)
    Interferometric sonar trackline navigation off Town Neck Beach in Sandwich, Massachusetts.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 17-May-2016
    Ending_Date: 23-May-2016
    Currentness_Reference:
    Ground condition of survey dates: 20160517-20160523. No geophysical data were collected on May 18 (JD 139), 21 (JD 142), and 22 (JD 143), 2016 ; 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 (66)
    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?
    2016-017-FA_SWATHplusTracklines
    Trackline for interferometric 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@_sxp where ### is the name of the trackline along which interferometric sonar data were collected, @ is the file iteration (a file iteration greater than 1 indicates that the survey line was split into multiple files during acquisition), and _sxp indicates that the file imported to CARIS was a SWATHplus processed file. For example, survey line 38 was interrupted 5 minutes into the line, the ship circled around to the location where surveying was paused, and the survey line was continued with recording to a new file; therefore, there are two tracklines for line 38: "l38f1" and "l38f2". (Source: USGS) String up to 12 characters
    Yr_JD_str
    Year and Julian day of the start of data collection for a specific survey line (YYYY-JD), 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. (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 (JD:HH:MM:SS), 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". (Source: USGS) 12 character string
    Yr_JD_end
    Year and Julian day of the end of data collection for a specific survey line (YYYY-JD), 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. (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 (JD:HH:MM:SS), 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". (Source: USGS) 12-character string
    SurveyID
    WHCMSC field activity identifier (e.g. "2016-017-FA" where 2016 is the survey year, 017 is survey number of that year, and FA is Field Activity). (Source: USGS) 11-character string
    VehicleID
    Name of the survey vessel used for data collection (e.g. "R/V Rafael") (Source: USGS) 10-character string
    DeviceID
    Name of the sonar device used to collect interferometric sonar data (e.g. "SWATHplus 234(M)") (Source: USGS) 15-character string
    Length_km
    Length of the swath survey line in kilometers (UTM Zone 18N, WGS 84) as calculated in the SQLite database. (Source: USGS)
    Range of values
    Minimum:0.28
    Maximum:3.41
    Units:kilometers
    Resolution:0.01

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 interferometric sonar data collected along these tracklines were collected by the U.S. Geological Survey off Town Neck Beach in Sandwich, Massachusetts, in May 2016 during USGS field activity 2016-017-FA. These data can be used to identify the extent of interferometric sonar (Systems Engineering and Assessment Ltd. SWATHplus-M, now Bathyswath) bathymetric and backscatter data that can be used conjunction with other geophysical and sample data to study sea-floor morphology and sediment texture.

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 sonar data.

    Type_of_Source_Media: disc
    Source_Contribution:
    This trackline navigation dataset documents the ship tracks along which interferometric sonar was collected by the US Geological Survey during field activity 2012016-017-FA. A 234-kHz Systems Engineering and Assessment Ltd. (SEA) SWATHplus-M (now Bathyswath) interferometric sonar was mounted on a rigid pole on the bow of the R/V Rafael. Data were acquired during May 2016.
    Configuration:
    Survey: Survey lines were run at an average speed of 5 knots and were generally spaced 30 m apart to obtain overlapping swaths of data and full SEABed 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 60-percent transmit power, a 34-cycle transmit pulse length, 4096 samples per channel, and a ping range of 46 meters.
    Speed of Sound: Sound-velocity profiles were collected several times each survey day with a hand-casted AML Minos X SVPT (Applied Microsystems) sound velocimeter.
    Tides: Tides were originally corrected during post-processing to Mean Sea Level using a NOAA-generated zone tidal model (stellwagen_tides.zdf) and the nearest NOAA-observed tide dataset (Boston_MSL_8443970_June2016.tid) that included all the survey dates. The final bathymetry surface was transformed to the NAVD88 reference surface using VDatum (version 3.9).
  2. How were the data generated, processed, and modified?
    Date: 2016 (process 1 of 5)
    Processing Step 1. Raw to Processed conversion for USGS field activity 2016-017-FA: Each raw SWATHplus bathymetric sonar file (SXR) was converted to a SWATHplus processed file (SXP) using SEA SWATHplus Swath Processor (ver. 3.07.17.00). During the conversion process, sound velocity profiles were used to minimize potential refraction artifacts from fluctuations in the speed of sound within the water column. Various bathymetric filters were applied to eliminate sounding outliers. Predicted tidal information was merged into the processed file (SXP) during this conversion, however final tidal corrections were applied later in the processing flow. Bathymetric filtering typically included low amplitude (100%), range (0-4 m), box (3-50 m depth, 1.5-75 m horizontal), median (window size of 5), alongtrack 1 (depth difference of 5 m, window size of 5 m, and learn rate of 0.7), alongtrack 2 (depth difference of 1.5 m, window size of 1 m, and learn rate of 0.9), and mean filters (0.25 m). These represent the typical parameters used for the majority of the survey but slight adjustments were required for some areas. 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
    Date: 2018 (process 2 of 5)
    Processing Step 2. CARIS preliminary processing for USGS field activity 2016-017-FA: A new CARIS HIPS project (ver. 10.1) was created for this field activity with projection information set to Universal Transverse Mercator (UTM) Zone 19, WGS 84. Each SWATHplus processed file (SXP) was imported to the new CARIS project using the Import/Conversion Wizard. Delayed heave from raw POS MV files was used to update HIPS survey lines using the import auxiliary data function. Navigation was reviewed and edited as needed using the navigation editor tool. Data were merged selecting no tide and the delayed heave source. A 2-m resolution Swath Angle Weighted (SWATH) surface was created to incorporate survey lines as they were processed, and the SWATH surfaces were reviewed for inconsistencies and anomalies. Beam-to-beam slopes and across track angle filters were applied to the soundings line by line and then further edited manually as needed. The refraction editor was used to adjust sound speed values in areas where velocimeter data did not adequately correct depth profiles obviously influenced by local anomalies in speed of sound through the water column. Survey lines were remerged and the surface was recalculated to incorporate processing edits. Preliminary processing was done during the survey and additional processing was done post-survey with CARIS HIPS and SIPS version 10.1. This process step was done between 2016 and 2018.
    Date: Oct-2018 (process 3 of 5)
    Processing Step 3. Python and Shell scripts were used to extract and reformat the navigation fixes stored in the CARIS HIPS database and add them to a SQLite database (version 3.27.1) that was geospatially extended using SpatiaLite (version 4.3.0a). The processing flow for this step follows:
    A. Extract navigation for each line in CARIS HDCS directory using the CARIS program printfNav for all the lines. (Extracted navigation file is tab-delimited in format YYYY-JD HH:MM:SS:FFF DD.LAT DD.LONG SSSSS_VVVVV_YYYY-JD_LLLL AR where YYYY=year, JD=Julian Day, HH=hour, MM=minute, SS=seconds, FFF=fractions of a second, DD.LAT=latitude in decimal degrees, DD.LONG=longitude in decimal degrees, SSSSS=survey name, VVVVV=vessel name, LLLL=linename, AR=accepted or rejected navigation fix.) This step creates TXT navigation files for each survey line in the CARIS project.
    B. A Python script (pySQLBathNav) runs on the navigation TXT files, creating a new line in the SQLite database (which is created if it does not already exist) for each record, with new fields for survey ID, vessel name, and system name. The pySQLBathNav script creates both point and polyline navigation for each survey line.
    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 (version 4.3.0_3).
    Date: Mar-2019 (process 4 of 5)
    Processing Step 4. QGIS (version 3.4) was used to clean up the attribute headings in the polyline shapefile's attribute table. Attributes for the survey line ('LineName'), year and Julian day survey line started ('Yr_JD_str'), Julian day and UTC time survey line started ('JD_UTC_str'), Year and Julian day survey line ended ('Yr_JD_end'), Julian day and UTC time survey line ended ('JD_UTC_end'), survey ID ('SurveyID'), survey vessel name ('VehicleID'), device used to collect the data ('DeviceID') and length field of each line ('Length_km') were already populated but renamed if necessary.
    Date: 07-Aug-2020 (process 5 of 5)
    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?
    USGS Field Activity 2016-017-FA: Navigation for the SWATHplus-M system was acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5), which blends Global Navigation Satellite Systems (GNSS) with acceleration data from a Inertial Measurement Unit (IMU) and GPS azimuthal heading. The POS MV was configured with two AeroAntenna Technologies GPS antennas located at either end of a 2-m baseline, which was oriented fore and aft and mounted atop the rigid pole on which the SWATHplus-M transducers were mounted at the bow of the R/V Rafael. DGPS positions were obtained from the primary antenna located on the forward end of the baseline, and the positional offsets between the antenna and the navigational reference point (the POS MV IMU) were accounted for in the Applanix POSView (version 8.60) acquisition software. DGPS positions are horizontally accurate to 0.5-2 meters, but accuracy can increase to less than 10 cm after post-processing with Applanix POSPac (version 8.1).
    Positional offsets were applied within the SWATHplus acquisition software (version 3.07.17.00) and stored within the SXR format data.
    Note that post-processed horizontal navigation data from the Applanix POS MV were applied for the bathymetry processing in CARIS software at a later date (see metadata from bathymetry file 2016-017-FA_Bathymetry2m_NAVD88); these tracklines represent the DGPS positions of the SWATHplus-M transducers as mounted on the bow of the R/V Rafael.
  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 SWATHplus trackline navigation that was collected during USGS field activity 2016-017-FA. Although this shapefile includes trackline navigation from all the swath sonar data, only shore parallel sonar data within the survey area were included in the final bathymetry raster (2016-017-FA_Bathymetry2m_NAVD88) and backscatter imagery (2016-017-FA_Backscatter) found in this report (https://doi.org/10.5066/P9HZHXXV). Time gaps occurred during this field activity where no surveying was done due to bad weather, rough seas and stops in surveying for equipment issues. No sonar data were collected on 20160518, 20160521, and 20160522 (May 18 (JD 139), 21 (JD 142), and 22 (JD 143), 2016) due to weather conditions, rough seas and equipment maintenance and (or) failure.
  5. How consistent are the relationships among the observations, including topology?
    Any spurious data points were removed during processing. There is no data for what would be line 8.

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)
    U.S. Geological Survey-ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2016-017-FA interferometric sonar navigation tracklines from offshore of Town Neck Beach in Sandwich, Massachusetts. This dataset contains a shapefile (2016-017-FA_SWATHplusTracklines.shp), browse graphic (2016-017-FA_SWATHplusTracklines_browse.jpg) and metadata files in 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 dataset contains data available in shapefile format. The user must have software capable of reading shapefile format to use the shapefile. Free geospatial data viewers can be found online.

Who wrote the metadata?

Dates:
Last modified: 07-Aug-2020
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)
sackerman@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/SB_data_release/DR_P9HZHXXV/2016-017-FA_SWATHplusTracklines_meta.faq.html>
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