Multibeam sonar tracklines collected during USGS field activity 2021-004-FA, using a dual-head Teledyne SeaBat T20-P multibeam echo sounder (Esri polyline shapefile, GCS WGS 84)

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Frequently anticipated questions:


What does this data set describe?

Title:
Multibeam sonar tracklines collected during USGS field activity 2021-004-FA, using a dual-head Teledyne SeaBat T20-P multibeam echo sounder (Esri polyline shapefile, GCS WGS 84)
Abstract:
The U.S. Geological Survey (USGS) Woods Hole Coastal and Marine Science Center (WHCMSC) completed a bathymetric and shallow seismic-reflection survey during the period of June 9, 2021 to June 24, 2021 in water depths from 2 m to 30 m for a portion of the outer Cape Cod nearshore environment between Marconi and Nauset Beaches. The products from this survey will help to support white shark research on their shallow-water behavior in the dynamic nearshore environment at Cape Cod National Seashore (CACO). CACO visitors’ safety is threatened by interactions between the public and white sharks. This project provides CACO with baseline data and information on nearshore white shark habitat, specifically in the nearshore shoreface, bathymetric trough, and longshore bar. This data release provides the geophysical data collected from outer Cape Cod during USGS Field Activities 2021-002-FA in 2021.
Supplemental_Information:
Support for 2021-004-FA was provided to the USGS from the National Park Service, Cape Cod National Seashore. Additional information on the field activities associated with this project are available at https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-004-FA
  1. How might this data set be cited?
    Ackerman, Seth D., 20231114, Multibeam sonar tracklines collected during USGS field activity 2021-004-FA, using a dual-head Teledyne SeaBat T20-P multibeam echo sounder (Esri polyline shapefile, GCS WGS 84): data release DOI:10.5066/P9GO90TI, 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., Worley, Charles R., and Nichols, Alexander R., 2023, High-resolution geophysical and geological data collected from outer Cape Cod, Massachusetts during USGS Field Activity 2021-004-FA: data release DOI:10.5066/P9GO90TI, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Ackerman, S.D., Foster, D.S., Worley, C.R., and Nichols, A.R., 2023, High-resolution geophysical and geological data collected from outer Cape Cod, Massachusetts during USGS Field Activity 2021-004-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9GO90TI.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -69.97780
    East_Bounding_Coordinate: -69.91390
    North_Bounding_Coordinate: 41.94270
    South_Bounding_Coordinate: 41.78360
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data-releases/media/2022/10.5066-P9GO90TI/f5a2ef99418a4c0897c1871ab811c086/2021-004-FA_SB424Tracklines_browse.jpg (JPEG)
    Thumbnail image of multibeam echo sounder tracklines collected from outer Cape Cod, Massachusetts.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 09-Jun-2021
    Ending_Date: 24-Jun-2021
    Currentness_Reference:
    ground condition
  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 (135)
    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 0.000005. Longitudes are given to the nearest 0.000005. 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?
    2021-004-FA_T20P_Tracklines.shp
    Shapefile of T20P multibeam echo sounder tracklines collected from outer Cape Cod, Massachusetts during USGS Field Activity 2021-004-FA. (Source: U.S. Geological Survey)
    LineName
    Hysweep HSX filename for the T20-P MBES trackline in the format: UTC Julian date and time (DDD_NNNN_HHMM format, i.e. '167_0030_1410', where DDD is the Julian date of the start of the line, NNNN is an optional planning number (typically 0000) and HHMM is hour minute in UTC time). In a few cases, a line restart resulted in a LineName where an additional _0001 was appended to the filename (for example '166_0000_1734_0001'). (Source: U.S. Geological Survey) Character set
    Year_JD
    Year and Julian day at the start of the survey line in the format: 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: U.S. Geological Survey) Character set
    StartTime
    Calendar date and UTC time at the start of the survey line in the format: YYYY-MM-DD HH:MM:SS.SSS, example "2021-06-20 13:23:50.210". (Source: U.S. Geological Survey) Character set
    EndTime
    Calendar date and UTC time at the end of the survey line in the format: YYYY-MM-DD HH:MM:SS.SSS, example "2021-06-20 14:22:54.831". (Source: U.S. Geological Survey) Character set
    TotalTime
    Total survey time for a particular trackline. Lines over 60 minutes in duration have the format HH:MM:SS.SSS; lines less than 60 minutes but more than 1 minute in duration have the format MM:SS.SSS (e.g. "59:04.621"), and lines less than 1 minute in duration have the format SS.SSS. (Source: U.S. Geological Survey) Character set
    SurveyID
    Woods Hole Coastal and Marine Science Center (WHCMSC) field activity identifier (e.g. "2021-004-FA" where 2021 is the survey year, 004 is survey number of that year, and FA is Field Activity). (Source: U.S. Geological Survey) Character set
    VehicleID
    Survey vessel name. (Source: U.S. Geological Survey) Character set
    DeviceID
    Sonar device used to collect MBES data. (Source: U.S. Geological Survey) Character set
    Length_km
    Length of T20P trackline in kilometers (UTM Zone 19N, WGS 84) calculated in CARIS. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0.006
    Maximum:12.166
    Units:kilometers
    Resolution:0.001

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Seth D. Ackerman
  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?

This dataset contains a polyline shapefile representing the trackline navigation for approximately 358 kilometers of multibeam echo sounder bathymetry and backscatter data collected by the U.S. Geological Survey during survey 2021-004-FA from outer Cape Cod, Massachusetts. This information can help spatially correlate the bathymetry and backscatter data with other geophysical data.

How was the data set created?

  1. From what previous works were the data drawn?
    Teledyne SeaBat T20P multibeam echo sounder raw bathymetry and backscatter (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, raw MBES data in HSX format.

    Type_of_Source_Media: disc
    Source_Contribution:
    Multibeam echosounder (MBES) bathymetry and backscatter data were collected using dual-head Teledyne SeaBat T20-P sonars. The pair of mills cross transmit and receive arrays were mounted side-by-side within a bracket that oriented them at opposing 30-degree angles (relative to horizontal). The bracket was pole-mounted on the starboard side of the R/V Rafael so that the sonar arrays were oriented athwart ships (primary and secondary arrays facing outward and down to port and starboard, respectively) and located approximately 1.235 m below the waterline when deployed. Vessel navigation and attitude data were acquired using an Applanix POS MV Wavemaster (model 220, V5) configured with two AeroAntenna Technologies GPS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the aft end of cabin, and the wetpod MRU mounted atop the sonar bracket just aft of the pole. An AML Micro X SV mounted on the sonar bracket monitored sound speed near the sonars during acquisition, and an AML Minos X SVPT was used to collect water column sound speed profiles 1 to 3 times each survey day. The Teledyne SeaBat User Interface (version 5.0.0.18) was used to control the sonars, which were operated in intermediate mode at full power (220 dB), with frequency-modulated pulses centered at 400 kHz. The range of across track beams (2048 for JD 160, 1024 for the rest of the survey) formed by the sonars were adjusted manually depending on water depth, and resulted in combined swath widths of 50 to 250 meters or typically 3 to 6 times the water depth. Data were monitored and recorded using the Teledyne SeaBat User Interface (UI) (version 5.0.0.18) and Hypack Hysweep (version 2021, 21.1.3.0). The SeaBat User Interface logged the navigation, attitude, bathymetry, time-series backscatter, and water column data to s7k format files for each sonar. The s7k line files were created by the Teledyne SeaBat UI using the following naming convention: M/S_YYYYMMDD_HHMMSS. The line files were appended with an "M" and "S" prefix to denote the port (or main/primary) "M" and "S" starboard (or secondary) sonar heads, respectively. Hypack Hysweep 2021 also was used to log the navigation, attitude, and bathymetry data for both sonars to a single HSX format file. Hypack Hysweep filenames have the format 'LLL_HHMM', where LLL indicates the three digit planned line number and HHMM is the UTC time. The Hypack Hysweep HSX data were used to produce the final processed bathymetry grid and the trackline shapefile.
  2. How were the data generated, processed, and modified?
    Date: Nov-2021 (process 1 of 3)
    PROCESSING STEP 1: CARIS HIPS DATA PROCESSING. Multibeam bathymetry processing within CARIS HIPS (version 11.3) post-survey consisted of the following flow:
    1) A vessel configuration file was created in CARIS for the HSX sonar files (RVRafael_DualT20P_2048.hvf for JD160 data, RVRafael_DualT20P.hvf for the rest of the survey) which includes, linear and angular installation offsets for each T20-P unit as well as vendor specified uncertainty values for each of the survey sensors.
    2) A CARIS HIPS project (version 11.3) was created with projection information set to Universal Transverse Mercator (UTM) Zone 19N, WGS84 using the vessel configuration file from step 1.1.
    3) Each HSX file was imported to the new CARIS project using the Import/Conversion Wizard.
    4) Delayed heave data from raw POS MV files (.000) were used to update HIPS survey lines using the import auxiliary data function.
    5) Post-processed navigation, vessel attitude, and GPS height data from POSPac SBET files, and post-processed RMS attitude error data from POSPac smrmsg files were used to update HIPS survey lines using the import auxiliary data function.
    6) Navigation source was set to Applanix SBET, and navigation was reviewed and edited as needed using the Navigation Editor tool.
    7) Georeference Bathymetry was done to apply the sound velocity corrections from the final SVP files containing all the sound velocity profiles collected for each survey day, specifying the nearest in time method, 'delayed' heave source, and use surface sound speed. SVP files for each survey day were created as part of the sound velocity profile processing workflow, see SVP dataset in the larger work citation.
    The steps described above were performed by Seth Ackerman between June and December 2021. The contact person for this and all subsequent processing steps below is Seth Ackerman. Person who carried out this activity:
    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
    Date: 15-Dec-2022 (process 2 of 3)
    PROCESSING STEP 2: EXPORT TRACKLINE NAVIGATION. All of the tracklines were selected in CARIS HIPS (version 11.4), then exported as a shapefile (File, Export, Selection, Shapefile...) using the coordinate reference system WGS 84 (EPSG:4326).
    Date: 06-Jan-2023 (process 3 of 3)
    PROCESING STEP 3: SHAPEFILE ATTRIBUTE TABLE FIELD ORGANIZATION:
    The trackline shapefile was loaded into an QGIS (version 3.28) project. Several fields representing CARIS HIPS processing parameters were removed. The remaining fields were renamed and reorganized using the QGIS attribute table editor into the final structure described in the Entity and Attribute information below. The QGIS tool 'Add Geometry Attributes' was used to calculate trackline length and 'Refactor' was used to set the precision for the trackline length field.
  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?
    Navigation data were acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5), which blends Global Navigation Satellite Systems (GNSS) data, acceleration data from a Motion Reference Unit (MRU) 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 athwartship and mounted atop the aft end of cabin. 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 11.00) 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 8.7).
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Data were collected on the following dates: 20210609 and 20210615-20210624 (Julian day 160 and 166-175); several lines of bathymetry data was collected on 20210609 (Julian day 160) while the survey team was out testing the seismic system before the formal start of the survey. Data collected during some turns were excluded from the final bathymetry dataset and backscatter mosaic. However, the patch test tracklines and tracklines that extend beyond the survey area are all included in this shapefile.
  5. How consistent are the relationships among the observations, including topology?
    Multibeam echo sounder (MBES) data were collected during survey operations in June 2021. Acquisition may have been suspended briefly during file changes or for longer periods during turns and system calibration, malfunction, or troubleshooting system issues. Any gaps between the polyline features in this shapefile reflect those time periods where data were not recorded.
    This trackline shapefile was created from the bathymetry data processed in Computer Aided Resource Information System Hydrographic Information Processing System CARIS HIPS version 11.3 using Hysweep HSX raw sonar files. Note that backscatter imagery (processed in QPS FMGT version 7.8.9) was created using the Teledyne SeaBat UI s7k raw files (M_ and S_ survey lines) that were collected simultaneously with the Hysweep HSX files. This polyline shapefile only represents the HSX tracklines which are generally the same extent as the s7k tracks. The s7k (M_ and S_) sonar files are mostly coincident with each other, although they can become unsynchronized. Any small timing offset only affects the timing of survey file changes and the resulting line names, not the quality of the data.

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 distributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Attn: Coastal and Marine Hazards and Resources Program
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    whsc_data_contact@usgs.gov
  2. What's the catalog number I need to order this data set? Multibeam echo sounder, Teledyne SeaBat T-20P tracklines, collected from outer Cape Cod, Massachusetts during USGS Field Activity 2021-004-FA: includes the shapefile 2021-004-FA_T20P_Tracklines.shp, the browse graphic 2021-004-FA_T20P_Tracklines_browse.jpg, and the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file 2021-004-FA_T20P_Tracklines_meta.xml.
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    To utilize these data, the user must have software capable of reading shapefile format, or GIS software.

Who wrote the metadata?

Dates:
Last modified: 14-Nov-2023
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
Metadata standard:
Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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