40 meter ESRI binary grid of single beam and swath bathymetry of inner continental shelf north of Cape Hatteras, NC to Virginia border (nhatt, UTM Zone 18N, WGS 84)

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Frequently anticipated questions:


What does this data set describe?

Title:
40 meter ESRI binary grid of single beam and swath bathymetry of inner continental shelf north of Cape Hatteras, NC to Virginia border (nhatt, UTM Zone 18N, WGS 84)
Abstract:
The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that mapped the Quaternary geologic framework of the estuaries, barrier islands, and inner continental shelf. This information provides a basis to understand the linkage between geologic framework, physical processes, and coastal evolution at time scales from storm events to millennia. The study area attracts significant tourism to its parks and beaches, contains a number of coastal communities, and supports a local fishing industry, all of which are impacted by coastal change. Knowledge derived from this research program can be used to mitigate hazards and facilitate effective management of this dynamic coastal system. This regional mapping project produced spatial datasets of high-resolution geophysical (bathymetry, backscatter intensity, and seismic reflection) and sedimentary (core and grab-sample) data. The high-resolution geophysical data were collected during numerous surveys within the back-barrier estuarine system, along the barrier island complex, in the nearshore, and along the inner continental shelf. Sediment cores were taken on the mainland and along the barrier islands, and both cores and grab samples were taken on the inner shelf. Data collection was a collaborative effort between the U.S. Geological Survey (USGS) and several other institutions including East Carolina University (ECU), the North Carolina Geological Survey, and the Virginia Institute of Marine Science (VIMS). The high-resolution geophysical data of the inner continental shelf were collected during six separate surveys conducted between 1999 and 2004 (four USGS surveys north of Cape Hatteras: 1999-045-FA, 2001-005-FA, 2002-012-FA, 2002-013-FA, and two USGS surveys south of Cape Hatteras: 2003-003-FA and 2004-003-FA) and cover more than 2600 square kilometers of the inner shelf. Single-beam bathymetry data were collected north of Cape Hatteras in 1999 using a Furuno fathometer. Swath bathymetry data were collected on all other inner shelf surveys using a SEA, Ltd. SwathPLUS 234-kHz bathymetric sonar. Chirp seismic data as well as sidescan-sonar data were collected with a Teledyne Benthos (Datasonics) SIS-1000 north of Cape Hatteras along with boomer seismic reflection data (cruises 1999-045-FA, 2001-005-FA, 2002-012-FA and 2002-013-FA). An Edgetech 512i was used to collect chirp seismic data south of Cape Hatteras (cruises 2003-003-FA and 2004-003-FA) along with a Klein 3000 sidescan-sonar system. Sediment samples were collected with a Van Veen grab sampler during four of the USGS surveys (1999-045-FA, 2001-005-FA, 2002-013-FA, and 2004-003-FA). Additional sediment core data along the inner shelf are provided from previously published studies. A cooperative study, between the North Carolina Geological Survey and the Minerals Management Service (MMS cores), collected vibracores along the inner continental shelf offshore of Nags Head, Kill Devils Hills and Kitty Hawk, North Carolina in 1996. The U.S. Army Corps of Engineers collected vibracores along the inner shelf offshore of Dare County in August 1995 (NDC cores) and July-August 1995 (SNL cores). These cores are curated by the North Carolina Geological Survey and were used as part of the ground validation process in this study. Nearshore geophysical and core data were collected by the Virginia Institute of Marine Science. The nearshore is defined here as the region between the 10-m isobath and the shoreline. High-resolution bathymetry, backscatter intensity, and chirp seismic data were collected between June 2002 and May 2004. Vibracore samples were collected in May and July 2005. Shallow subsurface geophysical data were acquired along the Outer Banks barrier islands using a ground-penetrating radar (GPR) system. Data were collected by East Carolina University from 2002 to 2005. Rotasonic cores (OBX cores) from five drilling operations were collected from 2002 to 2006 by the North Carolina Geological Survey as part of the cooperative study with the USGS. These cores are distributed throughout the Outer Banks as well as the mainland. The USGS collected seismic data for the Quaternary section within the Albemarle-Pamlico estuarine system between 2001 and 2004 during six surveys (2001-013-FA, 2002-015-FA, 2003-005-FA , 2003-042-FA, 2004-005-FA, and 2004-006-FA). These surveys used Geopulse Boomer and Knudsen Engineering Limited (KEL) 320BR Chirp systems, except cruise 2003-042-FA, which used an Edgetech 424 Chirp and a boomer system. The study area includes Albemarle Sound and selected tributary estuaries such as the South, Pungo, Alligator, and Pasquotank Rivers; Pamlico Sound and trunk estuaries including the Neuse and Pamlico Rivers; and back-barrier sounds including Currituck, Croatan, Roanoke, Core, and Bogue.
  1. How might this data set be cited?
    U.S. Geological Survey, 2013, 40 meter ESRI binary grid of single beam and swath bathymetry of inner continental shelf north of Cape Hatteras, NC to Virginia border (nhatt, UTM Zone 18N, WGS 84): Open-File Report 2011-1015, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Thieler, E.R., Foster, D.S., Mallinson, D.M., Himmelstoss, E.A., McNinch, J.E., List, J.H., and Hammar-Klose, E.S., 2013, Quaternary Geophysical Framework of the Northeastern North Carolina Coastal System: Open File Report 2011-1015, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -75.858571
    East_Bounding_Coordinate: -75.304870
    North_Bounding_Coordinate: 36.634388
    South_Bounding_Coordinate: 35.174139
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 07-Oct-1999
    Ending_Date: 20-Jul-2002
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster digital data
  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 4042 x 1225 x 1, type Grid Cell
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -75.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 40.000000
      Ordinates (y-coordinates) are specified to the nearest 40.000000
      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 Sea Level (MSL)
      Depth_Resolution: 9999
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?

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?
    E. Robert Thieler
    U.S. Geological Survey
    Research Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2350 (voice)
    508-457-2310 (FAX)
    rthieler@usgs.gov

Why was the data set created?

Swath and single-beam bathymetric data were collected along with sidescan-sonar, boomer and chirp sub-bottom geophysical data along the inner continental shelf study area. The single-beam and swath bathymetric data are used to define the regional seabed morphology within the study region. These data will augment the sidescan-sonar and chirp sub-bottom data.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata. (source 1 of 4)
    U.S. Geological Survey, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: Information unavailable from original metadata.
    Source_Contribution:
    Data were collected with a single-beam bathymetry system mounted to the side of the research vessel. It only provides depth information along the trackline of the ship. Sound velocity and motion sensor measurements were not collected.
    Information unavailable from original metadata. (source 2 of 4)
    U.S. Geological Survey, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: Information unavailable from original metadata.
    Source_Contribution:
    Data were collected with a swath bathymetric sonar system. The system is attached to the base of a pole mounted on the starboard side of the research vessel. Sound velocity measurements were acquired throughout the survey area to model the sound velocity structure of the water column and minimize refraction artifacts. Motion of the vessel (heave, pitch, roll) was recorded with a TSS DMS 2-05 motion sensor mounted directly above the SwathPlus transducers. DGPS navigation was used for vertical and horizontal positioning.
    Information unavailable from original metadata. (source 3 of 4)
    U.S. Geological Survey, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: Information unavailable from original metadata.
    Source_Contribution:
    Data were collected with a swath bathymetric sonar system. The system is attached to the base of a pole mounted on the starboard side of the research vessel. Sound velocity measurements were acquired throughout the survey area to model the sound velocity structure of the water column and minimize refraction artifacts. Motion of the vessel (heave, pitch, roll) was recorded with a TSS DMS 2-05 motion sensor mounted directly above the SwathPlus transducers. DGPS navigation was used for vertical and horizontal positioning.
    Information unavailable from original metadata. (source 4 of 4)
    U.S. Geological Survey, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: Information unavailable from original metadata.
    Source_Contribution:
    Data were collected with a swath bathymetric sonar system. The system is attached to the base of a pole mounted on the starboard side of the research vessel. Sound velocity measurements were acquired throughout the survey area to model the sound velocity structure of the water column and minimize refraction artifacts. Motion of the vessel (heave, pitch, roll) was recorded with a TSS DMS 2-05 motion sensor mounted directly above the SwathPlus transducers. DGPS navigation was used for vertical and horizontal positioning.
  2. How were the data generated, processed, and modified?
    Date: 2004 (process 1 of 15)
    For single-beam data collected in 1999: Bathymetric data were extracted from the survey navigation and stored as an ASCII file, listing longitude, latitude, and depth in meters. These data were then reformatted and loaded into MATLAB (MathWorks, Inc.). The trackline spacing during data acquisition was 300 meters. Within MATLAB (MathWorks, Inc), a median filter with a 15 pixel boxcar size was applied to the bathymetric data to remove spurious spikes and anomalous readings. In order to account for the distance of the transducer below the sea surface, one meter was added to the bathymetric values. These data were then corrected for tidal fluctuations. The ADCIRC circulation model was used to extract tidal coefficients at the locations along the cruise track. These processed values were then exported from Matlab as an ASCII file listing longitude, latitude and depth in meters. This process step and all subsequent process steps were performed by Erika Hammar-Klose. Person who carried out this activity:
    Erika Hammar-Klose (performed process); Jane Denny (contact)
    USGS
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    J.Denny 508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov
    Date: 2004 (process 2 of 15)
    For swath bathymetry data collected in 2001 and 2002: Bathymetric data were corrected for variations in the speed of sound throughout the water column; sound velocity profiles were acquired throughout the survey area using an Applied MicroSystems SVPlus Sound Velocimeter. These data were downloaded and reformatted to the required format needed for use within University of New Brunswick's Ocean Mapping Group (OMG) SwathEd multibeam processing software. The raw SwathPlus data were "unraveled" and reformatted into the OMG format. This process creates several files on disk: 1) bathymetric soundings, 2) raw backscatter, 3) navigation, and 4) parameter files describing the configuration of the system (i.e. offsets between motion reference unit and DGPS antenna, etc). This process also incorporates the sound velocity profiles in order to properly trace the travel path of the acoustic rays.
    Date: 2004 (process 3 of 15)
    The OMG formatted swath bathymetric data were then graphically edited using the SwathEd multibeam processing software. This enabled editing on a "ping-by-ping" basis, both in the across- and along-track dimension. Spurious or erroneous data were removed. The navigation data were also graphically examined for each line of data.
    Date: 2004 (process 4 of 15)
    Navigation data output during the unravel were reformatted for entry into MATLAB. The time of day and position were used to extract the tidal elevation from within the ADCIRC circulation model. The ADCIRC circulation model is referenced to Mean Sea Level. The tidal elevations were then written to an ASCII file and reformatted to OMG format for use within SwathEd. The tidal data were then written into the headers of the OMG formatted files, using the 'mergeTide' command. (an example of SwathEd Commands: binTide -year 2002 adcirc_ascii.txt tide.bin mergeTide -tide tide.bin *.merged )
    Date: 2004 (process 5 of 15)
    SwathEd Software was used to generate a blank grid at a 20m/pixel resolution into which the bathymetric data were written. make_blank areanumber_20m SwathEd software was then used to grid the bathymetric data utilizing the 'weigh_grid' command. The tidal elevations stored in the file headers are used by default during the gridding routine. weigh_grid -omg -butter -max_incidence 60 -maxdep -55 -mindep -4 -power 2 -cutoff 20 -lambda 10 areanumber_20m *.merged
    Date: 2004 (process 6 of 15)
    The 20 meter gridded data were then viewed using the SwathEd Jview command. The PatchTool was used to assess the roll misalignment of the data; slight roll misalignment artifacts were visible in the gridded data. After the needed adjustments were recorded, the configuration and navigation were remerged with the OMG bathymetric data using the mergeNav command. (mergeNav -use_params 0 -nav *.nav -swath *.merged) The remerged data were regridded for a second round of QC.
    Date: 2004 (process 7 of 15)
    The bathymetric data to this point have been edited, checked for navigation errors and corrected for tides (relative to MSL). Sound velocity corrections have been applied, and the roll misalignment was rectified. The 20 meter gridded data were exported as xyz ASCII file using the SwathEd command 'r4toASCII'. (r4toASCII areanumber_20m areanumber_20m.xyz)
    Date: 2004 (process 8 of 15)
    The 20 meter xyz data for each area (both single-beam data and swath bathymetry data) were imported into a GRASS database as a sites file. Command s.in.ascii input=areanumber_20m.xyz sites=areanumber_20m fs=. This sites file was interpolated at 40 meters using a regularized spline with tension gridding technique. s.surf.rst input=areanumber_20m elev=areanumber_40m dmin=20 tension=200 smooth=40 npmin=200 theta=45 scalex=40 The interpolated raster file was exported as an ASCII raster file. r.out.arc input=areanumber_40m output=areanumber_40m.asc
    Date: 2004 (process 9 of 15)
    Each area's .asc file was converted into an ESRI Grid using the ASCII to Raster utility in ArcToolbox (v9.1) under Conversion Tools > To Raster > ASCII to Raster.
    Date: 06-Nov-2004 (process 10 of 15)
    The individual grids for areas 1 through 10 (surveys from 1999, 2001, and 2002) were combined in GRASS using the "merge" command and smoothed with neighborhood statistics (mean, circle, 5 cells).
    Date: 06-Nov-2004 (process 11 of 15)
    The final, merged grid was clipped in ArcToolbox (v9.1) using Analysis Tools > Extract > Clip. A polygon coverage of the sidescan sonar extent was used to clip interpolated data that exceeded the survey coverage extent.
    Date: 15-Jun-2016 (process 12 of 15)
    Edits to the metadata were made to fix any errors that MP v 2.9.32 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). The link to the data catalog was fixed. The source information was incomplete and had to be modified to meet the standard. In the case of the depth resolution, the value of 9999 was entered to indicate that the original metadata did not contain the required information. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 13 of 15)
    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 14 of 15)
    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 15 of 15)
    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?
    These data were acquired during four surveys: 1999-045-FA, 2001-005-FA, 2002-012-FA and 2002-013-FA. The 1999 data were collected with a single-beam Furuno echo-sounder and the 2001-2002 data with a SEA, Ltd. SwathPLUS 234-kHz bathymetric sonar.
  2. How accurate are the geographic locations?
    All navigation data were acquired using the Differential Global Positioning Systems (DGPS). As such, horizontal accuracy is assumed to match that of DGPS: 1-3 meters (http://www.navcen.uscg.gov).
  3. How accurate are the heights or depths?
    Ship motion was recorded with a TSS DMS 2-05 Attitude Sensor, mounted on a head directly above the SwathPlus transducers. Navigation was recorded using Differential Global Positioning System (DGPS). Vertical accuracy is affected by the accuracy of both the navigation system and tidal measurements. DGPS vertical accuracy is assumed to be 0.2 meters. The data have been corrected for ship motion (roll, pitch, heave, and yaw). Tidal elevations were derived from the ADCIRC circulation model and referenced to Mean Sea Level (MSL). Changes in vessel draft due to fuel and water usage were not considered. The single-beam data was tide corrected and the draft of the transducer was accounted for during post-processing.
  4. Where are the gaps in the data? What is missing?
    All quality shore-parallel survey line bathymetric data that were collected within the inner continental shelf survey area north of Cape Hatteras to the Virginia border were incorporated in this grid. Soundings from both the single-beam and swath bathymetry surveys were processed and edited using the University of New Brunswick's Ocean Mapping Group (OMG) SwathEd multibeam processing software. Tielines (generally shore perpendicular) were not used in grid generation but used to verify tide corrections during post-processing. The single-beam bathymetry trackline spacing was 300 meters and only provided depth data directly along the track resulting in data gaps between tracklines. The swath bathymetry trackline spacing was 300 meters resulting in roughly 30 - 40% coverage with the SwathPlus bathymetric sonar. Thus, there are data gaps between tracklines. Both datasets were interpolated to fill areas of NODATA and generate a continuous bathymetric surface. Only the subset of bathymetry data collected north of Cape Hatteras has been included in this spatial dataset. Additional bathymetry data collected south of Cape Hatteras are included in a separate file available from: http://pubs.usgs.gov/of/2011/1015/data/bathymetry/innershelf/shatt.zip.
  5. How consistent are the relationships among the observations, including topology?
    This grid represents interpolated data; processed to account for gaps that occurred along-track and between adjacent lines.

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:
These data are not to be used for navigation purposes. Mariners should refer to the appropriate nautical chart. 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)
    E. Robert Thieler
    U.S. Geological Survey
    Research Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2350 (voice)
    508-457-2310 (FAX)
    rthieler@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  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?
    These data are available in Environmental Systems Research Institute (ESRI) GRID format. The user must have software capable of importing and processing the data file.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
Emily Himmelstoss
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA
USA

508-548-8700 x2262 (voice)
508-457-2310 (FAX)
ehimmelstoss@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/open_file_report/ofr2011-1015/nhatt.faq.html>
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