Multibeam Mapping of Selected Areas of the Outer Continental Shelf, Northwestern Gulf of Mexico

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?
    Title:
    Multibeam Mapping of Selected Areas of the Outer Continental Shelf, Northwestern Gulf of Mexico
    Abstract:
    ArcInfo GRID format data generated from the 1997 and 2002 multibeam sonar surveys, field activities A-1-97-GM and O-1-02-GM, of selected areas of the outer continental shelf, Northwestern Gulf of Mexico. The data include high-resolution bathymetry and calibrated acoustic backscatter. The specific areas include, East and West Flower Garden Banks, Stetson Bank, Alderdice Bank, Bright Bank, Rankin Banks, Geyer Bank, Jakkula Bank, McGrail Bank, Bouma Bank, MacNeil Bank, and Sonnier Bank.
    Supplemental_Information:
    Information about USGS Coastal and Marine Geology field activity A-1-97-GM are online at <http://walrus.wr.usgs.gov/infobank/a/a197gm/html/a-1-97-gm.meta.html> Information about USGS Coastal and Marine Geology field activity O-1-02-GM are online at <http://walrus.wr.usgs.gov/infobank/o/o102gm/html/o-1-02-gm.meta.html> >

  1. How should this data set be cited?

    United States Geological Survey, Coastal and Marine Geology (CMG), Chief, 2002, Multibeam Mapping of Selected Areas of the Outer Continental Shelf, Northwestern Gulf of Mexico.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -94.514
    East_Bounding_Coordinate: -91.486
    North_Bounding_Coordinate: 28.505
    South_Bounding_Coordinate: 27.491

  3. What does it look like?

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

    Beginning_Date: 12-Dec-1997
    Ending_Date: 28-Jun-2002
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: ArcInfo GRID

  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, 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: 15
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -93.00000
      Latitude_of_Projection_Origin: 0.00000
      False_Easting: 0.00
      False_Northing: 0.00

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 4.0 (5.0 for East and West Flower Garden Banks and Stetson Bank)
      Ordinates (y-coordinates) are specified to the nearest 4.0 (5.0 for East and West Flower Garden Banks and Stetson Bank)
      Planar coordinates are specified in Meters

      The horizontal datum used is WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.00 meters.
      The flattening of the ellipsoid used is 1/0.003352811.

      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 0.5% of the water depth
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Implicit coordinate

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
    ADBATHYG is an ArcInfo GRID with the following attributes: Cell Size = 4.000 Data Type: Floating Point Number of Rows = 1941 Number of Columns = 4453

    BOUNDARY Xmin = 589954.440 Xmax = 5607806.440 Ymin = 3103489.426 Ymax = 3111253.426

    STATISTICS Minimum Value = -106.859 Maximum Value = -60.987 Mean = -94.291 Standard Deviation = 4.918

    ADMOSG is an ArcInfo GRID with the following attributes: Cell Size = 4.000 Data Type: Floating Point Number of Rows = 1940 Number of Columns = 458

    BOUNDARY Xmin = 589958.436 Xmax = 607790.436 Ymin = 3103492.955 Ymax = 3111252.955

    STATISTICS Minimum Value 53.000 Maximum Value = 240.101 Mean = 194.337 Standard Deviation = 5.807

    Entity_and_Attribute_Detail_Citation: none

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?

    Peter Dartnell
    United States Geological Survey (USGS)
    Physical Scientist
    USGS, 400 Natural Bridges Drive
    Santa Cruz, CA 95060
    USA

    831-460-7415 (voice)
    (831-427-4748 (FAX)
    pdartnell@usgs.gov

Why was the data set created?
These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) or other software to display bathymetry and backscatter data of selected areas of the outer continental shelf, Northwestern Gulf of Mexico.

How was the data set created?
  1. From what previous works were the data drawn?

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

    Date: 28-Jun-2002 (process 1 of 1)
    The bathymetry and backscatter data were collected along a continuous swath perpendicular to the direction of the ship using a Kongsberg Simrad EM1000 multibeam sonar system for the 2002 survey and a Kongsberg Simrad EM300 multibeam sonar system for the 1997 survey. The data were cleaned of bad navigation and depth readings. Backscatter readings were converted from dB (decibels) to DN (digital number) using the convertion, ABSOLUTE VALUE(2DN/dB), where DN: 0-255 and dB: 0 - -127. The data were gridded into a common grid. The gridded data were converted to ArcInfo GRID format using ArcInfo's ASCIIGRID command.

    Person who carried out this activity:

    Peter Dartnell
    United States Geological Survey (USGS)
    Physical Scientist
    USGS, 400 Natural Bridges Drive
    Santa Cruz, CA 95060
    USA

    831-460-7415 (voice)
    831-427-4748 (FAX)
    pdartnell@usgs.gov

  3. What similar or related data should the user be aware of?

    United States Geological Survey, Coastal and Marine Geology (CMG), 20020917, USGS CMG O-1-02-GM Metadata.

    Online Links:

    This is part of the following larger work.

    United States Geological Survey, Coastal and Marine Geology (CMG), 20020917, USGS CMG InfoBank.

    Online Links:

How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?

    Not applicable for raster data.

  2. How accurate are the geographic locations?

    50 centimeters

  3. How accurate are the heights or depths?

    Not appicable

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

    Complete

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

    Unspecified

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:

Please recognize the U.S. Geological Survey (USGS) as the source of this information. USGS-authored or produced data and information are in the public domain.

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

    United States Geological Survey (USGS)
    Box 25286
    Denver, CO 80225
    USA

    (888)ASK-USGS (voice)

  2. What's the catalog number I need to order this data set?

    U.S. Geological Survey Open-file Report of02-411

  3. What legal disclaimers am I supposed to read?

    These data not intended for navigational purposes.

    Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, these data and information are provided with the understanding that they are not guaranteed to be usable, timely, accurate, or complete. Users are cautioned to consider carefully the provisional nature of these data and information before using them for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences. Conclusions drawn from, or actions undertaken on the basis of, such data and information are the sole responsibility of the user.

    Neither the U.S. Government nor any agency thereof, 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 data, software, information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights.

    Trade, firm, or product names and other references to non-USGS products and services are provided for information only and do not constitute endorsement or warranty, express or implied, by the USGS, USDOI, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.

  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 21-Aug-2002

Metadata author:
Pete Dartnell
United States Geological Survey (USGS)
Physical Scientist
USGS, MailStop 999, 345 Middlefield Road
Menlo Park, CA 94025-3561
USA

(650) 329-5460 (voice)
(650) 329-5411 (FAX)
pdartnell@usgs.gov

Metadata standard:
Content Standard for Digital Geospatial Metadata ("CSDGM version 2") (FGDC-STD-001-1998)

Generated by mp version 2.7.9 on Fri Jan 24 15:03:12 2003