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 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