5-meter interferometric bathymetry data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (32-bit GeoTIFF, UTM Zone 18N, WGS 84)

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Frequently anticipated questions:

What does this data set describe?

Title:
5-meter interferometric bathymetry data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (32-bit GeoTIFF, UTM Zone 18N, 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=2015-001-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, 5-meter interferometric bathymetry data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (32-bit GeoTIFF, UTM Zone 18N, 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: -75.912897
    East_Bounding_Coordinate: -75.133419
    North_Bounding_Coordinate: 37.849968
    South_Bounding_Coordinate: 36.987871
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2015-001-FA/data/bathymetry/2015-001-FA_bathy_browse.jpg (JPEG)
    Thumbnail image of regional bathymetry data for Delmarva Peninsula.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 10-Jun-2015
    Ending_Date: 14-Jul-2015
    Currentness_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: remote-sensing image
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 13689 x 19054 x 1, type Pixel
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18N
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -75
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000
      False_Northing: 0
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 5.0
      Ordinates (y-coordinates) are specified to the nearest 5.0
      Planar coordinates are specified in meters
      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.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    There are no attributes associated with a GeoTIFF. The "no data" value is set to 3.402823e+038.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

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?
    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?

These 5-m interpolated bathymetric data were created from swath interferometric bathymetry data. Bathymetric data are useful geophysical datasets for geologic framework studies. These data can be used in conjunction with other geophysical and sample data to identify sea-floor morphology.

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 interferometric data in .sxr format.

    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 BathySwath 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 from 20150610 to 20150704 (JD 161-185) at which point the MVP30 was not recovered from cast number: MVP30_0724. The remaining sound speed profiles on 20150704 through 20150714 (JD 185 - 195) were collected with an Applied Microsystems Minos (SVP) hand-deployed velocimeter. 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: 14-Jul-2015 (process 1 of 7)
    Each raw SWATHplus bathymetric sonar file (.sxr) was converted to a processed file (.sxp) using SWATHplus Processor (vers. 3.10.6.0). This software can import a nearly unlimited number of sound speed profiles and makes the process of recreating .sxp files much easier if the data need reprocessing. During the conversion process, sound speed profiles were used to minimize potential refraction artifacts from fluctuations in the speed of sound within the water column. Several bathymetric filters were applied to remove erroneous soundings and reduce the density of the data. Bathymetric filtering typically included low amplitude (100 percent), range (0-4 m), box (3-50 m depth, 1.5-75 m horizontal), median (window size 5), alongtrack 1 (depth difference of 5 m, window size 5 m, and learn rate of 0.7), alongtrack 2 (depth difference of 1.5 m, window size 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 USGS surveys although the values may have been adjusted slightly for specific parts of the survey area. Person who carried out this activity:
    U.S. Geological Survey
    Attn: William W. Danforth
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2274 (voice)
    508-457-2310 (FAX)
    bdanforth@usgs.gov
    Date: 14-Jul-2015 (process 2 of 7)
    A new CARIS HIPS project (vers. 9.0.14) was created with projection information set to Universal Transverse Mercator (UTM) Zone 18N, WGS 84. A vessel configuration file was created in CARIS for the Scarlett Isabella survey vessel, which included vendor specified uncertainty values for each of the survey sensors. Each BathySwath reprocessed file (sxp) was imported to the new CARIS project using the Import/Conversion Wizard. A 5-m resolution Bathymetry Associated with Statistical Error (BASE) surface was created from the files for each Julian day. The BASE surface for each day was reviewed for any inconsistencies or data anomalies. Navigation was reviewed and edited as needed using the navigation editor tool. Beam-to-beam slopes and across-track angle filters were applied to the soundings line by line. 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. Person who carried out this activity:
    U.S. Geological Survey
    Attn: William W. Danforth
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2274 (voice)
    508-457-2310 (FAX)
    bdanforth@usgs.gov
    Date: 01-Feb-2016 (process 3 of 7)
    Tide corrections (to MLLW) were applied within CARIS (version 9.0.14) using a discrete tidal-zoning model (DTZ) developed by NOAA/NOS's Hydrographic Planning Team (Huang, personal communication, 2010). The DTZ model corrects differences in tidal phase and amplitude between the survey area and observations made at NOS tide gauges at Atlantic City, NJ (8534720), Lewes, DE (8557380), Chesapeake Bay-Bridge-Tunnel, VA (8638863) and Duck NC (8651370). The tidal zone model was imported into CARIS (version: HIPS and SIPS 9.0.14) as a zone definition file (ZDF) and the observed tide data were loaded as CARIS .tid format files. Following tide correction, each line was re-merged and a BASE surface for the entire survey areas was computed to incorporate the MLLW observed tide information. Additional swath editing was done in CARIS using the swath and area based editors to remove additional inconsistencies and minimize survey artifacts. 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: 02-Feb-2016 (process 4 of 7)
    A Combined Uncertainty and Bathymetric Estimator (CUBE) surface was created in CARIS (version 9.0.19) after the survey using the uncertainty specifications of the survey instruments included in the vessel configuration file. Total Propagated Uncertainty (TPU) was calculated for each of the survey lines and the survey data was re-merged. The CUBE surface was created using IHO S-44 Order, Special Order specifications, with a Density and Locale Disambiguation method as a CUBE parameter. A nearest neighbor interpolation was performed on the CUBE surface in CARIS using a 3 x 3 matrix size (minimum: 6 node neighbors) to fill in some of the nadir gaps and empty grid cells. The CARIS HIPS interpolated CUBE surface was exported as a 5-m horizontal resolution 32-bit GeoTIFF (UTM Zone 18N, WGS 84) from CARIS, with pixel values (depths) ranging from -4.154 to -35.407 m. The GeoTIFF was imported into ArcGIS (version 10.3.1) and a corresponding world file was created using the EXPORT RASTER WORLD FILE tool. The TFW world file was created with the same prefix as the GeoTIFF and with .tfw extension. 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 7)
    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
    Date: 20-Jul-2018 (process 6 of 7)
    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: 08-Sep-2020 (process 7 of 7)
    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?
    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 acquired using an Ashtech Proflex 800. Positional offsets from the primary antenna to the MRU were corrected within the BathySwath acquisition software.
  3. How accurate are the heights or depths?
    Vertical accuracy of the raw data based on system specifications may be approximately 1 percent of water depth (0.1 to 0.4 m within the survey area). However, overall vertical accuracies on the order of 50 cm or better are assumed based on the following considerations: The Applanix Wavemaster POS MV Attitude and Positioning system, used to correct for vessel roll, pitch, heave, and yaw, has a theoretical vertical accuracy of a few mm. Tidal offsets were corrected to Mean Lower Low Water (MLLW) using a Zone Tidal Model supplied by the Hydrographic Planning Team at NOAA's National Ocean Service. Zone Tidal Models must conform to the International Hydrographic Organization (IHO) standards, which are within 30 cm vertical accuracy. Numerous sound speed profiles (more than 500) were acquired with a Brooke Ocean MVP30 moving vessel profiler and an Applied Microsystems Minos (SVP) hand-deployed velocimeter to minimize acoustic refraction artifacts in the bathymetry data. Sound speed data were entered into the BathySwath acquisition software to model the sound speed structure of the water column. Gridding algorithms and cell sizes for these data could introduce errors as great as 3 m along the edges of the data. Changes in ship draft due to water and fuel usage were not considered.
  4. Where are the gaps in the data? What is missing?
    Survey line bathymetry data that were collected within the Delmarva survey area were incorporated in this grid. The survey did not acquire complete coverage bathymetry data, as distance between adjacent survey lines was too great for overlapping swaths, resulting in gaps between survey lines. Interpolation was used to fill nadir gaps, but not gaps between survey lines.
  5. How consistent are the relationships among the observations, including topology?
    This grid represents interpolated swath interferometric bathymetry data at 5-m resolution. Quality control and data processing were conducted to remove spurious points and reduce sound speed artifacts (refraction). Soundings from the surveys were processed and edited using Computer Aided Resource Information System (CARIS) Hydrographic Information Processing System (HIPS; versions 9.0.14 and 9.0.19). Although the soundings were edited, small data spikes may still exist.

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. These data are not to be used for navigation.
  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 data from the Delmarva Peninsula area (2015-001-FA_bathy.zip). The zip file contains the following a GeoTIFF image in BigTIFF format: 2015-001-FA_bathy.tif, which has a TIFF world file, with the same image prefix name and a .tfw extension. A browse graphic (2015-001-FA_bathy_browse.jpg) and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2015-001-FA_bathy.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 WinZip file contains a GeoTIFF image files and associated metadata files. To utilize these data, the user must have software capable of viewing GeoTIFF image files.

Who wrote the metadata?

Dates:
Last modified: 19-Nov-2021
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)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the metadata contact is no longer with the USGS or the email is otherwise invalid.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/field_activities/2015_001_fa/2015-001-FA_bathy.faq.html>
Generated by mp version 2.9.50 on Fri Nov 19 13:02:55 2021