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 Mapping of Selected Areas of the Outer Continental Shelf, Northwestern Gulf of Mexico Geospatial_Data_Presentation_Form: XYZ ASCII Description: Abstract: XYZ ASCII format data generated from the 1997 and 2002 multibeam sonar surveys, field activities A-1-97-GM and O-1-02-GM, of selected areas of the outer continental shelf, Northwestern Gulf of Mexico. The data include high-resolution bathymetry and calibrated acoustic backscatter. The specific areas include, East and West Flower Garden Banks, Stetson Bank, Alderdice Bank, Bright Bank, Rankin Banks, Geyer Bank, Jakkula Bank, McGrail Bank, Bouma Bank, MacNeil Bank, and Sonnier Bank. 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 bathymetry and backscatter data of selected areas of the outer continental shelf, Northwestern Gulf of Mexico. Supplemental_Information: Information about USGS Coastal and Marine Geology field activity A-1-97-GM are online at Information about USGS Coastal and Marine Geology field activity O-1-02-GM are online at Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19971212 Ending_Date: 20020628 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -94.514 East_Bounding_Coordinate: -91.486 North_Bounding_Coordinate: 28.505 South_Bounding_Coordinate: 27.491 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Marine Geology Theme_Keyword: Multibeam Theme_Keyword: Bathymetry Theme_Keyword: Backscatter Theme_Keyword: Water Depth Theme_Keyword: Ocean Floor Topography Theme_Keyword: Deep-water Reefs Place: Place_Keyword_Thesaurus: None Place_Keyword: Northwestern Gulf of Mexico Place_Keyword: TX Place_Keyword: Gulf of Mexico 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, 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Country: USA Contact_Voice_Telephone: 831-460-7415 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: pdartnell@usgs.gov Cross_Reference: Citation_Information: Originator: United States Geological Survey (USGS), Coastal and Marine Geology (CMG) Publication_Date: 20020917 Title: USGS CMG O-1-02-GM Metadata Online_Linkage: http://walrus.wr.usgs.gov/infobank/o/o102gm/html/o-1-02-gm.meta.html Larger_Work_Citation: Citation_Information: Originator: United States Geological Survey (USGS), Coastal and Marine Geology (CMG) Publication_Date: 20020917 Title: USGS CMG InfoBank Online_Linkage: http://walrus.wr.usgs.gov/infobank/ 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: 50 centimeters Vertical_Positional_Accuracy Vertical_Positional_Accuracy_Report: Not applicable Lineage: Process_Step: Process_Description: The bathymetry and backscatter data were collected along a continuous swath perpendicular to the direction of the ship using a Kongsberg Simrad EM1000 multibeam sonar system for the 2002 survey and a Kongsberg Simrad EM300 multibeam sonar system for the 1997 survey. The data were cleaned of bad navigation and depth readings. Backscatter readings were converted from dB (decibels) to DN (digital number) using the convertion, ABSOLUTE VALUE(2DN/dB), where DN: 0-255 and dB: 0 - -127. The data were gridded into a common grid. The gridded data are converted to an XYZ ASCII format file (Longitude, Latitude, Attribute). Process_Date: 20020628 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: Physical Scientist Contact_Address: Address_Type: mailing and physical address Address: USGS, 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Country: USA Contact_Voice_Telephone: 831-460-7415 Contact_Facsimile_Telephone: 831-427-4748 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: 0.00004 (0.00005 for East and West Flower Garden Banks and Stetson Bank) Longitude_Resolution: 0.00004 (0.00005 for East and West Flower Garden Banks and Stetson Bank) 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 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Mean lower low water Depth_Resolution: 0.5% of the water depth Depth_Distance_Units: meters Depth_Encoding_Method: Implicit coordinate Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Sample of bathymetry XYZ ASCII file >Longitude, Latitude, Elevation >-86.57406,30.06655,-48.497 >-86.57399,30.06655,-48.473 >-86.57391,30.06655,-48.418 >-86.57383,30.06655,-48.408 >-86.57375,30.06655,-48.411 >-86.57368,30.06655,-48.415 >-86.57430,30.06648,-48.738 >-86.57422,30.06648,-48.728 >-86.57414,30.06648,-48.678 Sample of Backscatter XYZ ASCII file > Longitude, Latitude, DN Value >-86.57421,30.06640,207.696 >-86.57413,30.06640,206.398 >-86.57405,30.06640,203.770 >-86.57398,30.06640,201.170 >-86.57390,30.06640,201.098 >-86.57382,30.06640,202.064 >-86.57374,30.06640,202.693 >-86.57367,30.06640,202.720 >-86.57444,30.06632,201.992 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: Box 25286 City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: (888)ASK-USGS Resource_Description: U.S. Geological Survey Open-file Report of02-411 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: Fees: None Metadata_Reference_Information: Metadata_Date: 20020821 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