Multibeam Backscatter of the Los Angeles, California Margin

Metadata also available as

Metadata:


Identification_Information:

Citation:
Citation_Information:
Originator:
United States Geological Survey (USGS), Coastal and Marine Geology (CMG), Chief Scientist (James V. Gardner)
Publication_Date: 2002
Title: Multibeam Backscatter of the Los Angeles, California Margin
Geospatial_Data_Presentation_Form: XYZ ASCII

Description:
Abstract:
XYZ ASCII 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. These datasets in their present form were not originally intended for publication. The bathymetry and backscatter have data-collection and processing artifacts. These data are being made public to satisfy a Freedom of Information Act request. 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: 19961029
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 determined.

Logical_Consistency_Report: Point features present.

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 Kongsberg Simrad EM300, EM1000, and dual EM3000 multibeam sonar systems. The data are cleaned of bad navigation and depth readings and corrected for tides to mean lower low water datum. The depth 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.
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: Geologist
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: Point

Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Point


Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.00002, 0.00004
Longitude_Resolution: 0.00002, 0.00004
Geographic_Coordinate_Units: Decimal degrees
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:

Sample of Backscatter XYZ ASCII file

 Longitude, Latitude, DN Value
(decimal degree, decimal degree, DN value)
-117.97421,33.63640,207.696
-117.97413,33.63640,206.398
-117.97405,33.63640,203.770
-117.97398,33.63640,201.170
-117.97390,33.63640,201.098
-117.97382,33.63640,202.064
-117.97374,33.63640,202.693
-117.97367,33.63640,202.720
-117.97444,33.63640,201.992
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: ASCII
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: Pete 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


Generated by mp version 2.8.11 on Fri May 21 11:37:15 2004