GLORIA_GEOG.TIF - Composite GLORIA sidescan sonar image of the Gulf of Mexico (Geographic)

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

Frequently-anticipated questions:


What does this data set describe?

Title:
GLORIA_GEOG.TIF - Composite GLORIA sidescan sonar image of the Gulf of Mexico (Geographic)
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_GEOG.TIF - Composite GLORIA sidescan sonar image of the Gulf of Mexico (Geographic): 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: -96.001492
    East_Bounding_Coordinate: -82.070679
    North_Bounding_Coordinate: 29.501377
    South_Bounding_Coordinate: 23.002703

  3. What does it look like?

    <http://pubs.usgs.gov/of/2005/1071/data/sidescan/imagery/gloria/geog/gloria_geog-thumb.gif> (GIF)
    Thumbnail image of the Gulf of Mexico GLORIA sidescan sonar mosaic.
    <http://pubs.usgs.gov/of/2005/1071/data/sidescan/imagery/gloria/geog/gloria_geog.gif> (GIF)
    Overview image of the Gulf of Mexico GLORIA sidescan sonar mosaic.

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

    Calendar_Date: 02-Feb-1982
    Currentness_Reference: ground condition

  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 2880 x 5537 x 1, type Pixel

    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 .00000. Longitudes are given to the nearest .00000. 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?

    Band_1

    ObjectID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Value

    Red

    Green

    Blue

    Entity_and_Attribute_Overview:
    There are no attributes associated with a GeoTIFF image.

    Pixel values contain acoustic reflectivity values normalized to an 8-bit data range (0-255). Low-backscatter is represented by dark tones (low values) and high-backscatter is represented by bright tones (high values). These data have been radiometrically enhanced for better viewing.


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

    508-457-8700 x 2266 (voice)
    508-457-2310 (FAX)
    dtwichell@usgs.gov


Why was the data set created?

This GIS data layer is a 250 m version of the composite Gulf of Mexico GLORIA sidescan sonar image mosaic that is in a geographic projection using the WGS84 datum. The GLORIA imagery was collected during 1982 and 1985 and covers 490,563 km2 of the Gulf of Mexico in water deeper than approximately 300 m. A discussion of these data can be found in EEZ Scan 85 Scientific Staff (1987).


How was the data set created?

  1. From what previous works were the data drawn?

    mos01.tif - mos16.tif (source 1 of 1)
    Paskevich, V.F., 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
    Type_of_Source_Media: CD-ROM
    Source_Contribution:
    A composite GLORIA sidescan sonar mosaic of the Gulf of Mexico that had been completed at a 250 m pixel size and was projected from Albers Equal Area to a geographic coordinate system utilizing the PCI Remote Sensing software re-projection utility. The NAD27 datum was used in both cases.

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

    Date: 04-Sep-1998 (process 1 of 4)
    The 16 individual 50m per pixel GLORIA digital sidescan sonar mosaics were resampled to 250 m per pixel and combined using an Albers Equal Area projection to create an overview digital mosaic of the Gulf of Mexico using PCI software.

    Person who carried out this activity:

    Valerie Paskevich
    U.S. Geological Survey
    Information Specialist / GIS Coordinator
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2281 (voice)
    (508) 457-2310 (FAX)
    vpaskevich@usgs.gov

    Data sources used in this process:
    • mos01.tif - mos16.tif

    Data sources produced in this process:

    • compos.pix

    Date: 09-Aug-1999 (process 2 of 4)
    The completed 250 m per pixel Gulf of Mexico GLORIA mosaic was reprojected from Albers Equal Area to geographic coordinate system using the NAD 27 datum utilizing the PCI Remote Sensing software reprojection utility.

    Person who carried out this activity:

    Valerie Paskevich
    U.S. Geological Survey
    Information Specialist / GIS Coordinator
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2281 (voice)
    (508) 457-2310 (FAX)
    vpaskevich@usgs.gov

    Data sources used in this process:
    • compos.pix

    Data sources produced in this process:

    • latlon.pix

    Date: 09-Aug-1999 (process 3 of 4)
    The reprojected 250 m per pixel Gulf of Mexico GLORIA mosaic was exported as a GeoTIFF image with an associated "world" file using the PCI Remote Sensing software export utility.

    Person who carried out this activity:

    Valerie Paskevich
    U.S. Geological Survey
    Information Specialist / GIS Coordinator
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2281 (voice)
    (508) 457-2310 (FAX)
    vpaskevich@usgs.gov

    Data sources used in this process:
    • latlon.pix

    Data sources produced in this process:

    • latlon.tif

    Date: 17-Sep-2004 (process 4 of 4)
    The GLORIA tiff image was reprojected from the geographic projection using the NAD 27 datum to a geographic projection using the WGS 84 datum. The reprojection was done using Geographic Transformer (v. 5.1) produced by Blue Marble. The affine transform mode was used, the pixel size was 250 m, and the central latitude was 26.25N.

    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:
    • latlon.tif

    Data sources produced in this process:

    • gloria_geog.tif

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

    Paskevich, V., 2000, Gulf of Mexico GLORIA sidescan sonar geologic interpretation: ArcView data coverages: Open-File Report 00-019, U.S. Geological Survey, Woods Hole Science Center.

    Other_Citation_Details: 1 CD-ROM
    EEZ-Scan 85 Scientific Staff, 1987, Atlas of the U.S. Exclusive Economic Zone Gulf of Mexico and Eastern Caribbean Areas: Miscellaneous Investigations Series I-1864-A, U.S. Geological Survey, Reston, VA.


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?

    All available data were used to compile this mosaic.

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

    All these data were collected using the 6.2-6.8 kHz GLORIA sidescan sonar system. The majority of the data used in this mosaic were acquired using a 45 km total swath width, and the data were originally mapped to a 50 m pixel size.


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)

    U.S. Geological Survey
    c/o David Twichell
    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?

    This image is available as a GeoTIFF image with an accompanying world file. To utilize this data, the user must have an image viewer, image processing or GIS software package capable of importing a GEOTIFF image.


Who wrote the metadata?

Dates:
Last modified: 22-Feb-2005
Metadata author:
U.S. Geological Survey
c/o David Twichell
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 09:34:44 2005