Trackline navigation for swath interferometric bathymetry data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (Esri polyline shapefile, GCS WGS 84).

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Frequently anticipated questions:


What does this data set describe?

Title:
Trackline navigation for swath interferometric bathymetry data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (Esri polyline shapefile, GCS WGS 84).
Abstract:
The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy in the fall of 2012. The U.S. Geological Survey conducted cruises during the summers of 2014 and 2015 to map the inner continental shelf of the Delmarva Peninsula using geophysical and sampling techniques to define the geologic framework that governs coastal system evolution at storm-event and longer timescales. Geophysical data collected during the cruises include swath bathymetric, sidescan sonar, chirp and boomer seismic reflection profiles, grab sample and bottom photograph data. More information about the USGS survey conducted as part of the Hurricane Sandy Response-- Geologic Framework and Coastal Vulnerability Study can be found at the project website or on the WHCMSC Field Activity Web pages: https://woodshole.er.usgs.gov/project-pages/delmarva/, https://cmgds.marine.usgs.gov/fan_info.php?fan=2014-002-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-001-FA. Data collected during the 2014 survey can be obtained here: https://doi.org/10.5066/F7MW2F60
  1. How might this data set be cited?
    U.S. Geological Survey, 2016, Trackline navigation for swath interferometric bathymetry data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (Esri polyline shapefile, GCS WGS 84).: data release DOI:10.5066/F7P55KK3, 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.

    Sweeney, Edward M., Pendleton, Elizabeth A., Ackerman, Seth D., Andrews, Brian D., Baldwin, Wayne E., Danforth, William W., Foster, David S., Thieler, E. Robert, and Brothers, Laura L., 2016, High-resolution geophysical data collected along the Delmarva Peninsula 2015, U.S. Geological Survey Field Activity 2015-001-FA: data release DOI:10.5066/F7P55KK3, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -75.891093
    East_Bounding_Coordinate: -75.156754
    North_Bounding_Coordinate: 37.838746
    South_Bounding_Coordinate: 36.999545
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2015-001-FA/data/bathymetry/tracklines/2015-001-FA_bathytracks_browse.jpg (JPEG)
    Thumbnail image of swath bathymetry tracklines for Delmarva Peninsula.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 10-Jun-2015
    Ending_Date: 14-Jul-2015Currentness_Reference:
    ground condition; data were not collected on 20150628 (transition between Legs 1 and 2 of the survey)
  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):
      • Entity point (706)
    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?
    2015-001-FA_bathytracks
    Swath bathymetry tracklines for survey 2015-001-FA along the Delmarva Peninsula. (Source: U.S. Geological Survey)
    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 the trackline along which swath bathymetric data were collected in the format: line number (i.e. 'l1') + file number (i.e. 'f1') + bathymetry file type (i.e. '_sxp'). (Source: U.S. Geological Survey) Character set
    Yr_JD_ini
    Year and Julian date 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
    JD_UTC_ini
    Julian day and UTC time at the start of the survey line in the format: JD:HH:MM:SS; 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
    Yr_JD_end
    Year and Julian date at the end of the survey line. (Source: U.S. Geological Survey) Character set
    JD_UTC_end
    JulianDay:HH:MM:SS of the end of the survey line. (Source: U.S. Geological Survey) Character set
    SurveyID
    WHCMSC field activity identifier (e.g. "2015-001-FA" where 2015 is the survey year, 001 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 swath bathymetry. (Source: U.S. Geological Survey) Character set
    Length_km
    Length of swath data line in kilometers (UTM Zone 18N, WGS84). (Source: U.S. Geological Survey)
    Range of values
    Minimum:0.14
    Maximum:22.218
    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)
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Edward M. Sweeney
    U.S. Geological Survey
    Physical Scientist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2256 (voice)
    508-457-2310 (FAX)
    emsweeney@usgs.gov

Why was the data set created?

This dataset contains trackline navigation for approximately 5,500 km of swath interferometric bathymetry data collected by the U.S. Geological Survey during cruise 2015-001-FA along the Delmarva Peninsula, MD and VA. This information can help spatially correlate the bathymetric data with other data in the GIS.

How was the data set created?

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

    Type_of_Source_Media: disc
    Source_Contribution:
    USGS used a 234 kHz Systems Engineering and Assessment Ltd. (SEA) SWATHplus-M (now Bathyswath) interferometric sonar pole-mounted on the port side of the M/V Scarlett Isabella. Survey lines were run at an average speed of 5 knots and were spaced 200 m apart in the nearshore to approximately 3-km apart in the offshore. Full data coverage was obtained for sidescan sonar data, but not for bathymetric data. The SEA SWATHplus-M operates at a variable range (increased or decreased manually depending on water depth, but generally 85 m on both sides). The system was operated with a transmit power of 80 percent, a transmit length of 43 cycles, and 4096 samples per channel. Sound-velocity profiles were collected continuously with an ODIM MVP30 moving vessel profiler. Tides were corrected using a zone tidal model with observed tides from gauges in Atlantic City, NJ; Lewes, DE; Chesapeake Bay-Bridge-Tunnel, VA; and Duck, NC.
  2. How were the data generated, processed, and modified?
    Date: 2015 (process 1 of 5)
    Survey navigation information is stored within each raw (.sxr) data file. Each raw SWATHPlus bathymetric sonar file (.sxr) was converted to a SWATHplus processed file (.sxp) using SEA SWATHplus Swath Processor (vers. 3.10.6.0). This step and subsequent steps were performed by Wayne Baldwin. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Wayne Baldwin
    Physical Scientist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2015 (process 2 of 5)
    A new Computer Aided Resource Information System (CARIS) Hydrographic Information Processing System (HIPS) project (vers. 9.0.14) was created with projection information set to Universal Transverse Mercator (UTM) Zone 18N, WGS 84. Each SWATHplus processed file (sxp) was imported to the new CARIS project using the Import/Conversion Wizard. Navigation was checked and edited as needed using the Navigation Editor tool. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Wayne Baldwin
    Physical Scientist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2015 (process 3 of 5)
    AWK, Python and Shell scripts were used to extract and reformat the navigation fixes stored in the CARIS HIPS database and add them to a geospatial SQLite (version 3.7.9) database. 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 the directory of TXT navigation files for each survey line in the CARIS project.
    B. The output TXT files from the printfNav process are parsed to remove rejected navigation records then reformatted into CSV files containing additional fields for survey ID, vessel name and system name using Shell and AWK scripts.
    C. A Python script (pySQLBathNav) runs on each reformatted CSV file parsing the file from each record and adding points to a SQLite database (which is created if it does not already exist). The pySQLBathNav script creates both point and trackline navigation for each survey line.
    D. When all of the survey lines have been processed into SQLite database, a polyline shapefile is exported from the database using the spatialite_tool command (Spatialite version 3.0.1).
    Steps B, C and D were all run within a shell script called printfnavconv. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Wayne Baldwin
    Physical Scientist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2015 (process 4 of 5)
    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' remained the same), Year and Julian day ('Year_JD_init' was changed to 'Yr_JD_ini') survey line started, Julian day and UTC time ('JD_UTC_init' was changed to 'JD_UTC_ini') survey line started, Year and Julian day that the survey line ended ('Year_JD_end' was changed to 'Yr_JD_end'), Julian day and UTC time that the survey line ended ('JD_UTC_end' remained the same), survey ID ('SurveyID' remained the same), survey vessel name ('VehicleID' remained the same), device used to collect the data ('DeviceID' remained the same) and length field ('Length_km' remained the same). Person who carried out this activity:
    U.S. Geological Survey
    Attn: Edward M. Sweeney
    Physical Scientist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2256 (voice)
    508-457-2310 (FAX)
    emsweeney@usgs.gov
    Date: 19-Apr-2017 (process 5 of 5)
    The online links to the data were updated to reflect the new server hosting the data. Additionally, other small edits could be made to the metadata, such as modifying http to https where appropriate. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. 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?
    Pendleton, Elizabeth A., Ackerman, Seth D., Baldwin, Wayne E., Danforth, William W., Foster, David S., Thieler, E. Robert, and Brothers, Laura L., 2015, High-resolution geophysical data collected along the Delmarva Peninsula 2014, U.S. Geological Survey Field Activity 2014-002-FA: data release DOI:10.5066/F7MW2F60, 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?
    Navigation data were acquired in WGS 84 coordinate system with an Applanix Wavemaster POS MV, which blends Global Navigation Satellite Systems (GNSS) with acceleration data from a Motion Reference Unit (MRU) and GPS azimuthal heading. The POS MV uses a dual antenna array with a designated primary and secondary antenna. Positions from the primary (forward) Applanix antenna were sent via Ethernet satellite link (from a KVH Mini-VSAT Broadband receiver) to shore stations in MD and VA. Returned Radio Technical Commission for Maritime Services (RTCM) 3.1 position corrections were passed through to the Applanix Wavemaster and applied to the Submetrix System for Real Time Kinematic (RTK) position solutions (accurate to less than 1 m, horizontally). Backup Differential Global Positioning System + Wide Area Augmentation System (DGPS+WAAS), which is accurate to within 2 m horizontally, were also acquired using an Ashtech Proflex 800; however, the backup DGPS and WAAS data were not implemented into the bathymetry data since the primary POS MV positioning provided continuous data throughout the survey. Positional offsets from the primary antenna to the MRU were corrected within the BathySwath acquisition software.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This shapefile includes trackline navigation from all the swath bathymetric data that was collected within the survey area. However, only quality sonar data along the main survey lines were included in the final bathymetry grid. Noisy or poor quality data were not included in the grid, but the line navigation are included in this shapefile. Data along tie and transit lines were not included in the final grid or in the navigation shapefile.
  5. How consistent are the relationships among the observations, including topology?
    These swath bathymetry data were collected at 200 meter line spacing. The M/V Scarlet Isabella can only survey in water depths greater than 8 meters, so there are some gaps in the survey lines where the vessel had to avoid crossing shallow shoals. Most of the gaps were planned with breaks in tracklines or maneuvers around the shoals. Most of the data were acquired roughly parallel to the orientation of Assateague Island at an average speed of 5 knots. Line numbering begins at line 1 and ends at line 183. Any spurious bathymetry navigation data points were removed during processing.

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 originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    Edward M. Sweeney
    U.S. Geological Survey
    Physical Scientist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2256 (voice)
    508-457-2310 (FAX)
    emsweeney@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2015-001-FA bathymetry trackline data from the Delmarva Peninsula area (2015-001-FA_bathytracks.zip). The zip file contains a folder with the following shapefile: 2015-001-FA_bathytracks.shp, a browse graphic (2015-001-FA_bathytracks_browse.jpg) and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2015-001-FA_bathytracks.xml) in four standard formats are also included in the zip file.
  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 shapefile format. The user must have software capable of reading shapefile format to use these data.

Who wrote the metadata?

Dates:
Last modified: 19-Apr-2017
Metadata author:
Edward M. Sweeney
U.S. Geological Survey
Physical Scientist
384 Woods Hole Road
Woods Hole, Massachusetts
USA

508-548-8700 x2256 (voice)
508-457-2310 (FAX)
emsweeney@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.36 on Wed Apr 19 13:25:37 2017