Identification_Information: Citation: Citation_Information: Originator: Center for Coastal & Ocean Mapping, University of New Hampshire Publication_Date: 2007 Title: Raw Kongsberg Simrad EM120 Multibeam Data Geospatial_Data_Presentation_Form: remote-sensing image Description: Abstract: High-quality, full coverage, processed Multibeam bathymetry and acoustic backscatter Data - Data were reduced for position, elevation, orientation, water-column sound-speed and refraction effects and are provided in a cleaned fully integrated form in ASCII longitude, latitude, depth (bathymetry) or longitude, latitude, 8-bit backscatter value format. All raw and reduced data include quality flags, indicating whether these data were rejected or deemed to be outside deliverable survey specifications. Purpose: The National Oceanic and Atmospheric Administration (NOAA), on behalf of the United States Government, has a requirement to carry out surveys of specific regions on the continental margin (slope and rise) in the northern Gulf of Mexico in order to obtain multibeam bathymetry and co-registered calibrated acoustic backscatter. These data are required to support any potential claim for extended jurisdiction by the United States under United Nations Convention on the Law of the Sea (UNCLOS) Article 76. The requirement is for the collection and processing of high quality, full-coverage multibeam sonar data in water depths of approximately 2000 to 4000 m in order to precisely define the location of the 2500-m isobath and the "foot of the slope" as defined under UNCLOS Article 76. As part of their NOAA-funded research program, University of New Hampshire (CCOM/UNH) researchers oversaw data acquisition, processing and archiving of the data collected during the cruise. Supplemental_Information: C&C Technologies Inc., Lafayette, LA was responsible for all aspects of the data acquisition. Raw data were fully processed and then grids were produced by CCOM/UNH aboard ship. This metadata is for the Kongsberg Simrad raw.all datagram. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 180/2007 Ending_Date: 180/2007 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -84.845502300110 East_Bounding_Coordinate: -84.592265118547 North_Bounding_Coordinate: 25.488384781554 South_Bounding_Coordinate: 25.211782390392 Keywords: Theme: Theme_Keyword_Thesaurus: Theme_Keyword: Multibeam bathymetry Theme_Keyword: Multibeam Acoustic Backscatter Theme_Keyword: Kongsberg Simrad raw.all datagram Theme_Keyword: Processed OMG/SwathEd Theme: Place: Place_Keyword: Continental Margin Place_Keyword: Northeast Gulf of Mexico Place_Keyword: Florida Escarpment Place_Keyword: Foot of the Slope Access_Constraints: None Use_Constraints: None Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Center for Coastal & Ocean Mapping, University of New Hampshire Contact_Person: James V. Gardner Contact_Position: Research Professor Contact_Address: Address_Type: mailing and physical address Address: Chase Ocean Engineering Lab, 24 Colovos Road City: Durham State_or_Province: NH Postal_Code: 03824 Country: USA Contact_Voice_Telephone: 603-862-3473 Contact_Facsimile_Telephone: 603-862-0839 Contact_Electronic_Mail_Address: jim.gardner@unh.edu Hours_of_Service: 9 AM - 5 PM EST Security_Information: Security_Classification: Unclassified Native_Data_Set_Environment: Kongsberg Simrad binary raw.all format Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: A Kongsberg Simrad EM120 12-kHz multibeam sonar was used with effective beam widths no greater than 1° x 2° (transmit fore-aft x receive athwart ship) at -3 dB, with swaths of ~7.4 times water depth in water depths between 2000 and 4000 m, with depth accuracies of the swath of better than ±0.3% of water depth at these depths. All data meets this specification. Descriptions of the systems and offsets applied can be found within the cruise report at http://www.ccom.unh.edu/law_of_the_sea.html. In addition to bathymetry data, full time-series backscatter values were recorded across each beam footprint. Backscatter values were corrected for outgoing signal strength, receiver gains, spherical spreading, and attenuation. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal positioning of the vessel was determined using C&C Technologies C-Nav Real Time Gypsy (RTG)-aided DGPS integrated into a TSS DMS-05 motion sensor. Positioning is accurate to better than 0.1 meters (at 95% confidence) during all surveying. All positioning is referenced to the WGS84 Datum. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Center for Coastal & Ocean Mapping, University of New Hampshire Publication_Date: 2007 Title: Processed OMG/Swathed Files Type_of_Source_Media: digital Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2007 Source_Currentness_Reference: publication date Process_Step: Process_Description: Kongsberg Simrad EM120 datagrams were acquired with a Kongsberg Simrad Neptune data-acquisition system. Process_Date: 2007 Process_Time: 2007/180 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Center for Coastal & Ocean Mapping, University of New Hampshire Contact_Address: Address_Type: Mailing and Physical Address Address: Chase Ocean Engineering Lab, 24 Colovos Road City: Durham State_or_Province: NH Postal_Code: 03824 Country: USA Contact_Voice_Telephone: (603) 862-3473 Contact_Electronic_Mail_Address: jim.gardner@unh.edu Hours_of_Service: 9am -5pm Spatial_Reference_Information: Geodetic_Model: Horizontal_Datum_Name: WGS 84 Ellipsoid_Name: Geodetic Reference System 80 Vertical_Coordinate_System_Definition: instantaneous sea level Backscaatter_System_Definition: Backscatter_Datum_Name: decibel Depth_Resolution: Depth_Distance_Units: Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Center for Coastal & Ocean Mapping, University of New Hampshire Contact_Person: James V. Gardner Resource_Description: Downloadable Data Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Kongsberg Simrad binary raw.all Format_Information_Content: Kongsberg Simrad datagram Transfer_Size: 17MB Digital_Transfer_Option: Offline_Option: Recording_Format: Metadata_Reference_Information: Metadata_Date: 2004 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Center for Coastal & Ocean Mapping, University of New Hampshire Contact_Person: James V. Gardner Contact_Position: Research Professor Contact_Address: Address_Type: mailing and physical address Address: Case Ocean Engineering Lab, 24 Colovos Road City: Durham State_or_Province: NH Postal_Code: 3824 Country: USA Contact_Voice_Telephone: 603-862-3473 Contact_Facsimile_Telephone: 603-862-0839 Contact_Electronic_Mail_Address: jim.gardner@unh.edu Hours_of_Service: M-F 9am-5pm Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time Metadata_Access_Constraints: None Metadata_Use_Constraints: None Metadata_Security_Information: Metadata_Security_Classification: Unclassified