Identification_Information: 


  Citation: 
    Citation_Information: 
      Originator: 
        United States Geological Survey (USGS), 
        Coastal and Marine Geology (CMG), 
        Chief Scientist (Peter Dartnell) 
      Publication_Date: 2004
      Title: 
        Multibeam Backscatter of the Los Angeles, California Margin
      Geospatial_Data_Presentation_Form: ESRI ArcInfo GRID  


  Description: 
    Abstract: 
      ESRI ArcInfo GRID format data generated from the 1996, 1998, and 1999 
      multibeam sonar surveys of the Los Angeles, California Margin. 
      The data include high-resolution corrected acoustic backscatter. 
      Disclaimer: These datasets in their present form were not originally 
      intended for publication. The  bathymetry and backscatter are full of 
      data-collection and processing artifacts. Outside influences beyond our 
      control required us to publish these datasets in their present form. 
      Care must be taken not to confuse artifacts with real seafloor morphology 
      and acoustic backscatter.
    Purpose: 
      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 Los Angeles, California Margin. 
    Supplemental_Information: 
      Information for USGS Coastal and Marine Geology related 
      activities are online at 
      <http://walrus.wr.usgs.gov/infobank/c/c196sc/html/c-1-96-sc.meta.html>
      <http://walrus.wr.usgs.gov/infobank/a/a398sc/html/a-3-98-sc.meta.html>
      <http://walrus.wr.usgs.gov/infobank/c/c199sc/html/c-1-99-sc.meta.html>


  Time_Period_of_Content: 
    Time_Period_Information: 
      Range_of_Dates/Times: 
        Beginning_Date: 19960930
        Ending_Date: 19990518
    Currentness_Reference: ground condition

  Status: 
    Progress: Complete
    Maintenance_and_Update_Frequency: As needed


  Spatial_Domain: 
    Bounding_Coordinates: 
      West_Bounding_Coordinate: -118.850
      East_Bounding_Coordinate: -117.754
      North_Bounding_Coordinate: 34.029
      South_Bounding_Coordinate: 33.334


  Keywords: 
    Theme: 
       Theme_Keyword_Thesaurus: GCMD DIF, Version 5.0a, September 1996: Parameter Keywords
       Theme_Keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry
       Theme_Keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography
       Theme_Keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography > Water Depth

    Theme:
       Theme_Keyword_Thesaurus: None
       Theme_Keyword: Marine Geology
       Theme_Keyword: Multibeam
       Theme_Keyword: Acoustic Backscatter
       Theme_Keyword: Backscatter

    Place: 
      Place_Keyword_Thesaurus: None
      Place_Keyword: Los Angeles Margin
      Place_Keyword: CA
      Place_Keyword: Southern California
      Place_Keyword: USA


  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. 

  Point_of_Contact: 
    Contact_Information: 
      Contact_Person_Primary: 
        Contact_Person: Peter Dartnell
        Contact_Organization: 
          United States Geological Survey (USGS)
          Coastal and Marine Geology (CMG)
      Contact_Position: Physical Scientist
      Contact_Address: 
        Address_Type: mailing and physical address
        Address: USGS, MailStop 999, 345 Middlefield Road
        City: Menlo Park
        State_or_Province: CA
        Postal_Code: 94025-3561
        Country: USA
      Contact_Voice_Telephone: (650) 329-5460
      Contact_Facsimile_Telephone: (650) 329-5411
      Contact_Electronic_Mail_Address: pdartnell@usgs.gov






Data_Quality_Information: 


  Attribute_Accuracy: 
    Attribute_Accuracy_Report: Not applicable for raster data.


  Logical_Consistency_Report: Unspecified


  Completeness_Report: Complete


  Positional_Accuracy: 
    Horizontal_Positional_Accuracy: 
      Horizontal_Positional_Accuracy_Report: 0.5 meters
    Vertical_Positional_Accuracy
      Vertical_Positional_Accuracy_Report: 0.05 percent of the water depth. Depths corrected to mean lower low water datum.


  Lineage: 
    Process_Step: 
      Process_Description: 
        The multibeam bathymetry and acoustic backscatter data were collected 
        along a continuous swath perpendicular to the direction 
        of the ship using a Kongsberg Simrad EM1000 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.
      Process_Date: 19961030
      Process_Contact: 
        Contact_Information: 
          Contact_Person_Primary: 
            Contact_Person: Peter Dartnell
            Contact_Organization: 
              United States Geological Survey (USGS)
              Coastal and Marine Geology (CMG)
          Contact_Position: Peter Dartnell
          Contact_Address: 
            Address_Type: mailing and physical address
            Address: USGS, MailStop 999, 345 Middlefield Road
            City: Menlo Park
            State_or_Province: CA
            Postal_Code: 94025-3561
            Country: USA
          Contact_Voice_Telephone: (650) 329-5460
          Contact_Facsimile_Telephone: (650) 329-5411
          Contact_Electronic_Mail_Address: pdartnell@usgs.gov






Spatial_Data_Organization_Information: 


  Direct_Spatial_Reference_Method: Raster


  Raster_Object_Information: 
    Raster_Object_Type: Grid Cell
       
Spatial_Reference_Information: 


  Horizontal_Coordinate_System_Definition: 
    Planar: 
      Grid_Coordinate_System: 
        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_Coordinate_Information: 
        Planar_Coordinate_Encoding_Method: coordinate pair
        Coordinate_Representation: 
          Abscissa_Resolution: 2.0, 4.0, 8.0
          Ordinate_Resolution: 2.0, 4.0, 8.0
        Planar_Distance_Units: Meters
    Geodetic_Model: 
      Horizontal_Datum_Name: WGS84
      Ellipsoid_Name: WGS84
      Semi-major_Axis: 6378137.00 meters
      Denominator_of_Flattening_Ratio: 0.003352811


Entity_and_Attribute_Information: 


  Overview_Description: 
    Entity_and_Attribute_Overview: 
      dumemosg is an ESRI ArcInfo GRID with the following attributes (example):
      Cell Size = 2.000         
      Data Type: Floating Point
      Number of Rows = 1020
      Number of Columns = 6310

      BOUNDARY                                
      Xmin =               332279.651                
      Xmax =               344899.651              
      Ymin =              3762484.488             
      Ymax =              3764524.488                            

      STATISTICS
      Minimum Value = 47.001
      Maximum Value =  250.000
      Mean          = 188.934
      Standard Deviation = 6.718



    Entity_and_Attribute_Detail_Citation: none  





Distribution_Information: 


  Distributor: 
    Contact_Information: 
      Contact_Organization_Primary: 
        Contact_Organization: 
          United States Geological Survey (USGS)
          Information Services
      Contact_Address: 
        Address_Type: mailing and physical address
        Address: 345 Middlefield Rd., MS-999
        City: Menlo Park
        State_or_Province: CA
        Postal_Code: 94025
        Country: USA
      Contact_Voice_Telephone: (650)329-5460


  Resource_Description: C-1-96-SC, A-3-98-SC, and C-1-99-SC data sets


  Distribution_Liability

    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.



  Standard_Order_Process: 
    Digital_Form: 
      Digital_Transfer_Information: 
        Format_Name: ArcInfo GRID
        Format_Version_Number: 8.0.2
      Digital_Transfer_Option: 
        Online_Option: 
          Computer_Contact_Information: 
            Network_Address: 
              Network_Resource_Name: 
                none
    Fees: None






Metadata_Reference_Information: 


  Metadata_Date: 20040412



  Metadata_Contact: 
    Contact_Information: 
      Contact_Person_Primary: 
        Contact_Person: Peter Dartnell
        Contact_Organization: 
          United States Geological Survey (USGS)
          Coastal and Marine Geology (CMG)
      Contact_Position: Physical Scientist
      Contact_Address: 
        Address_Type: mailing and physical address
        Address: USGS, MailStop 999, 345 Middlefield Road
        City: Menlo Park
        State_or_Province: CA
        Postal_Code: 94025-3561
        Country: USA
      Contact_Voice_Telephone: (650) 329-5460
      Contact_Facsimile_Telephone: (650) 329-5411
      Contact_Electronic_Mail_Address: pdartnell@usgs.gov


  Metadata_Standard_Name: 

    Content Standard for Digital Geospatial Metadata 
    ("CSDGM version 2")


  Metadata_Standard_Version: FGDC-STD-001-1998


  Metadata_Time_Convention: universal time