Multibeam Backscatter of the Newport Shelf and Slope Region, California

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?

    Multibeam Backscatter of the Newport Shelf and Slope Region, California
    XYZ ASCII format data generated from the 1998 multibeam sonar survey of the Newport Shelf and Slope Region, California. The data include high-resolution acoustic, calibrated backscatter.
    Information for USGS Coastal and Marine Geology related activities are online at < <> >

  1. How should this data set be cited?

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

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -118.699
    East_Bounding_Coordinate: -117.749
    North_Bounding_Coordinate: 33.852
    South_Bounding_Coordinate: 33.336

  3. What does it look like?

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

    Beginning_Date: 26-Mar-1998
    Ending_Date: 11-Apr-1998
    Currentness_Reference: ground condition

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

    Geospatial_Data_Presentation_Form: XYZ ASCII

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Point data set. It contains the following vector data types (SDTS terminology):

      • Point

    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 0.00016. Longitudes are given to the nearest 0.00016. Latitude and longitude values are specified in Decimal degrees.

      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?


    Sample of Backscatter XYZ ASCII file

     Longitude, Latitude, DN Value
    (decimal degree, decimal degree, DN value)
    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)
    USGS, MailStop 999, 345 Middlefield Road
    Menlo Park, CA 94025-3561

    (650) 329-5469 (voice)
    (650) 329-5411 (FAX)

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 the Newport Shelf and Slope Region, 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: 11-Apr-1998 (process 1 of 1)
    The multibeam bathymetry and acoustic backscatter data were collected along a continuous swath perpendicular to the direction of the ship using a Kongsberg Simrad EM300 multibeam sonar system. The data are cleaned of bad navigation and depth readings 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. The GRID was converted to an XYZ ASCII file by using the GRIDPOINT, ADDXY, and Tables' UNLOAD commands.

    Person who carried out this activity:

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

    (650) 329-5469 (voice)
    (650) 329-5411 (FAX)

  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 determined.

  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?


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

    Point features present.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None

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

    (650)329-5469 (voice)

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

    A-3-98-SC data set

  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?

Last modified: 06-Feb-2002

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

(650) 329-5460 (voice)
(650) 329-5411 (FAX)

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 15:49:55 2002