Multibeam Mapping of the Mid and Outer Shelf, Head of De Soto Canyon, Northeastern Gulf of Mexico

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  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 data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

Title:

Multibeam Mapping of the Mid and Outer Shelf, Head of De Soto Canyon, Northeastern Gulf of Mexico

Abstract:

ArcInfo GRID format data generated from the 2002 multibeam sonar survey, field activity M-1-02-GM, of the head of De Soto Canyon, Northeastern Gulf of Mexico. The data include high-resolution bathymetry and calibrated acoustic backscatter.

Supplemental_Information:

Information about USGS Coastal and Marine Geology field activity M-1-02-GM are online at <http://walrus.wr.usgs.gov/infobank/m/m102gm/html/m-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 the Mid and Outer Shelf, Head of De Soto Canyon, Northeastern Gulf of Mexico.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -87.58

   East_Bounding_Coordinate: -86.50

   North_Bounding_Coordinate: 30.16

   South_Bounding_Coordinate: 29.50

3. What does it look like?

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

   Beginning_Date: 17-Jun-2002

   Ending_Date: 09-Jul-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: 16

      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.9996

      Longitude_of_Central_Meridian: -87.00000

      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 8.0
      Ordinates (y-coordinates) are specified to the nearest 8.0
      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 (Simrad EM1000). 5 centimeters (Simrad EM3000).

      Depth_Distance_Units: meters

      Depth_Encoding_Method: Implicit coordinate

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   NTHBATHG is an ArcInfo GRID with the following attributes: Cell Size = 8.000 Data Type: Floating Point Number of Rows = 2848 Number of Columns = 3155

   BOUNDARY Xmin = 514471.079 Xmax = 539711.079 Ymin = 3311737.928 Ymax = 3334521.928

   STATISTICS Minimum Value = -107.178 Maximum Value = -39.811 Mean = -73.520 Standard Deviation = 16.604

   NTHMOSG is an ArcInfo GRID with the following attributes: Cell Size = 8.000 Data Type: Floating Point Number of Rows = 2370 Number of Columns = 3163

   BOUNDARY Xmin = 514447.343 Xmax = 539751.343 Ymin = 3315561.286 Ymax = 3334521.286

   STATISTICS Minimum Value = 27.000 Maximum Value = 224.344 Mean = 188.365 Standard Deviation = 7.004

   CENBATHG is an ArcInfo GRID with the following attributes: Cell Size = 8.000 Data Type: Floating Point Number of Rows = 5391 Number of Columns = 5804

   BOUNDARY Xmin = 471227.542 Xmax = 517659.542 Ymin = 3291574.324 Ymax = 3334702.324

   STATISTICS Minimum Value = -146.640 Maximum Value = -38.600 Mean = -80.610 Standard Deviation = 22.121

   CENMOSG is an ArcInfo GRID with the following attributes: Cell Size = 8.000 Data Type: Floating Point Number of Rows = 5410 Number of Columns = 5804

   BOUNDARY Xmin = 471227.215 Xmax = 517659.215 Ymin = 3291447.342 Ymax = 3334727.342

   STATISTICS Minimum Value = 18.000 Maximum Value = 235.553 Mean = 193.388 Standard Deviation = 8.921

   STHBATHG is an ArcInfo GRID with the following attributes: Cell Size = 8.000 Data Type: Floating Point Number of Rows = 5628 Number of Columns = 3926

   BOUNDARY Xmin = 445545.785 Xmax = 476953.785 Ymin = 3264439.695 Ymax = 3309463.695

   STATISTICS Minimum Value = -245.510 Maximum Value = -35.610 Mean = -80.211 Standard Deviation = 33.998

   STHMOSG is an ArcInfo GRID with the following attributes: Cell Size = 8.000 Data Type: Floating Point Number of Rows = 5628 Number of Columns = 3990

   BOUNDARY Xmin = 445038.094 Xmax = 476958.094 Ymin = 3264439.640 Ymax = 3309463.640

   STATISTICS Minimum Value = 19.001 Maximum Value = 241.236 Mean = 196.344 Standard Deviation = 6.142

   Entity_and_Attribute_Detail_Citation: none

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • United States Geological Survey (USGS),

2. Who also contributed to the data set?

3. To whom should users address questions about the data?

   James V. Gardner
   United States Geological Survey (USGS)
   Geologist
   USGS, MailStop 999, 345 Middlefield Road
   Menlo Park, CA 94025-3561
   USA
   

   (650) 329-5469 (voice)
   (650) 329-5411 (FAX)
   jvgardner@usgs.gov
   

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 the head of De Soto Canyon, Northeastern Gulf of Mexico.

1. From what previous works were the data drawn?

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

   Date: 30-Aug-2002 (process 1 of 1)

   The bathymetry and backscatter data were collected along a continuous swath perpendicular to the direction of the ship using Kongsberg Simrad EM1000 and EM3000D multibeam sonar systems. The data are 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 depth readings are gridded into a common grid. The gridded data are converted to ArcInfo GRID format using ArcInfo's ASCIIGRID command.

   Person who carried out this activity:
   

   James V. Gardner
   United States Geological Survey (USGS)
   Geologist
   USGS, MailStop 999, 345 Middlefield Road
   Menlo Park, CA 94025-3561
   USA
   

   (650) 329-5469 (voice)
   (650) 329-5411 (FAX)
   jvgardner@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 M-1-02-GM Metadata.

   Online Links:

   • <http://walrus.wr.usgs.gov/infobank/m/m102gm/html/m-1-02-gm.meta.html>

   This is part of the following larger work.

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

   Online Links:

   • <http://walrus.wr.usgs.gov/infobank/>

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 applicable

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

   Complete

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

   Unspecified

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 02-XXX

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?
   • Availability in digital form:

     Data format:	ArcInfo GRID (version 8.0.2)
     Network links:	<http://geopubs.wr.usgs.gov/open-file/of02-XXX>

   • Cost to order the data: None

Dates:

Last modified: 27-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)