GLORIA_BRIGHT_NAD83.SHP - Areas of high-backscatter on the GLORIA sidescan sonar image

Metadata also available as - [Outline] - [Parseable text]

Frequently-anticipated questions:


What does this data set describe?

Title:
GLORIA_BRIGHT_NAD83.SHP - Areas of high-backscatter on the GLORIA sidescan sonar image
Abstract:
This GIS overlay is a component of the U.S. Geological Survey, Woods Hole Science Center's, Gulf of Mexico GIS database. The Gulf of Mexico GIS database is intended to organize and display USGS held data and provide on-line (WWW) access to the data and/or metadata.
  1. How should this data set be cited?

    Twichell, David, 2005, GLORIA_BRIGHT_NAD83.SHP - Areas of high-backscatter on the GLORIA sidescan sonar image: Open-File Report 2005-1071, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    D.C., Twichell, V.A., Cross, Paskevich, V.F., Hutchinson, D.R., Winters, W.J., and Hart, P.E., 2005, GIS of selected geophysical and core data in the northern Gulf of Mexico continental slope collected by the U.S. Geological Survey: Open-File report 2005-1071, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details: 1 DVD-ROM

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -93.592427
    East_Bounding_Coordinate: -88.067145
    North_Bounding_Coordinate: 28.644747
    South_Bounding_Coordinate: 26.408149

  3. What does it look like?

    <http://pubs.usgs.gov/of/2005/1071/data/sidescan/interpretation/gloria/gloria_bright_nad83.gif> (GIF)
    Overview image showing the extent and coverage of the data layer.
    <http://pubs.usgs.gov/of/2005/1071/data/sidescan/interpretation/gloria/gloria_bright_nad83-thumb.gif> (GIF)
    Thumbnail image showing the extent and coverage of the data layer.

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 02-Feb-1982
    Ending_Date: 22-Oct-1985
    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):

      • G-polygon (131)

    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 0.005. Longitudes are given to the nearest 0.005. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

  7. How does the data set describe geographic features?

    gloria_bright_nad83
    Shapefile Attribute Table (Source: ESRI)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    polygon (Source: ESRI)

    Coordinates defining the features.

    ID
    Internal Feature Number (Source: ESRI)

    ValueDefinition
    0 


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?

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov


Why was the data set created?

This GIS data layer shows the areas of high acoustic backscatter on the GLORIA sidescan sonar image form the Gulf of Mexico. The interpretation was completed by David Twichell using the GLORIA image in concert with the multibeam bathymetry to identify areas of high backscatter that are not associated with steep slopes.


How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Paskevich, V., 2000, Gulf of Mexico GLORIA sidescan sonar geologic interpretation: ArcView data coverages: Open-File Report 00-019, U.S. Geological SUrvey, COastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details: 1 CD-ROM

  2. How were the data generated, processed, and modified?

    Date: Unknown (process 1 of 3)
    This interpretive layer shows the areas of high backscatter on the GLORIA image that are not associated with steep topography or mass-wasting deposits. The shapefile was created in ArcView using 250 m GLORIA sidescan image (gloria.tif) to identify areas of high backscatter. Only those areas that were not associated with steep slopes (derived from comparing This GIS data layer with a slope steepness map derived from the multibeam bathymetry) nor mass-wasting deposits (derived from comparing This GIS data layer with the masswasting shapefile) were included in This GIS data layer.

    Person who carried out this activity:

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov

    Data sources used in this process:
    • gloria.tif

    Data sources produced in this process:

    • gloria_bright.shp

    (process 2 of 3)
    Metadata imported.

    Data sources used in this process:

    • C:\GOMGIS\data\sidescan\interpretation\gloria\gloria_coverage.shp.xml

    (process 3 of 3)
    Dataset projected froom NAD27 to NAD83 using Arctoolbox 9.0.

    Data sources used in this process:

    • gloria_bright.shp

    Data sources produced in this process:

    • gloria_bright_nad83.shp

  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?

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

  5. How consistent are the relationships among the observations, including topology?

    The data layer has been checked for topological consisitency (Clean and Build completed).


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 (USGS) as the source of this information.

  1. Who distributes the data set? (Distributor 1 of 1)

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@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?

    Although this data set has been used by the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. 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?

    The data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS® or ArcView® 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing data. A free data viewer, arcexplorer, capable of displaying the data is available from ESRI at www.esri.com.


Who wrote the metadata?

Dates:
Last modified: 13-Dec-2005
Metadata author:
David Twichell
U.S. Geological Survey
Oceanographer
384 Woods Hole Road
Woods Hole, MA 02543-1598
USA

(508) 548-8700 x2266 (voice)
(508) 457-2310 (FAX)
dtwichell@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


Generated by mp version 2.8.6 on Tue Dec 13 13:24:40 2005