Multibeam Backscatter of the Long Beach Shelf, California

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?
    Title: Multibeam Backscatter of the Long Beach Shelf, California
    Abstract:
    ArcInfo GRID format data generated from the 1999 multibeam sonar survey of the Long Beach Shelf, California. The data include high-resolution acoustic, calibrated backscatter.
    Supplemental_Information:
    Information for USGS Coastal and Marine Geology related activities are online at < <http://walrus.wr.usgs.gov/infobank/c/c199sc/html/c-1-99-sc.meta.html>

  1. How should this data set be cited?

    United States Geological Survey, Coastal and Marine Geology (CMG), Chief, 2002, Multibeam Backscatter of the Long Beach Shelf, California.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -118.357
    East_Bounding_Coordinate: -117.816
    North_Bounding_Coordinate: 33.732
    South_Bounding_Coordinate: 33.541

  3. What does it look like?

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

    Beginning_Date: 14-Apr-1999
    Ending_Date: 18-May-1999
    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: 11
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -117.00000
      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 16.0
      Ordinates (y-coordinates) are specified to the nearest 16.0
      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.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
    LBMOSG is an ArcInfo GRID with the following attributes: Cell Size = 16.000 Data Type: Floating Point Number of Rows = 1292 Number of Columns = 3124

    BOUNDARY Xmin = 374236.586 Xmax = 424220.586 Ymin = 3712060.650 Ymax = 3732732.650

    STATISTICS Minimum Value = 97.999 Maximum Value = 226.999 Mean = 195.972 Standard Deviation = 5.694

    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?

    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

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 acoustic backscatter data of the Long Beach Shelf, California.

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: 18-May-1999 (process 1 of 1)
    The multibeam acoustic backscatter data were collected along a continuous swath perpendicular to the direction of the ship using a Kongsberg Simrad dual EM3000 multibeam sonar system. The data are cleaned of bad navigation and depth readings and corrected for tides to mean lower low water datum. The acoustic backscatter 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?

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?

    0.5 meters

  3. How accurate are the heights or depths?

    0.05 percent of the water depth. Depths corrected to mean lower low water datum.

  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)
    345 Middlefield Rd., MS-999
    Menlo Park, CA 94025
    USA

    (650)329-5469 (voice)

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

    C-1-99-SC data sets

  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: 06-Feb-2002

Metadata author:
Peter 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 Wed Mar 20 15:02:41 2002