Identification_Information: Citation: Citation_Information: Originator:Originator: NOAA Pacific Island Fisheries Science Center Coral Reef Ecosystem Division Pacific Islands Benthic Habitat Mapping Center Publication_Date: 20070501 Title: Reson 8101 multibeam backscatter data from the banktop and bank edge environments of Ofu, Olosega, and Ta'u Islands of the Manua Island group, American Samoa Geospatial_Data_Presentation_Form: digital data Online_Linkage: http://www.soest.hawaii.edu/pibhmc/ Description: Abstract: Multibeam backscatter imagery extracted from gridded bathymetry of Ofu, Olosega, and Ta'u Islands of the Manua Island Group, American Samoa, South Pacific. These data provide coverage between 0 and 350 meters. The backscatter dataset includes data collected using a Reson 8101, 240 kHz multibeam sonar. These metadata are for the 1 m grid cell size Reson 8101 multibeam backscatter data only. Purpose: The GeoTIFFs of backscatter imagery were created using data gathered from multibeam soundings for use as a planning and reference document. The data are also being used for benthic habitat mapping, for locating Essential Fish Habitat, and for studying geologic features of the area. Refer to supplemental information for description of instrument and survey. Supplemental_Information: Multibeam data were collected aboard the R/V AHI (Acoustic Habitat Investigator), a 25’ survey launch owned and operated by the NOAA Pacific Islands Fisheries Science Center in Honolulu, HI. The R/V AHI’s survey sensors include a 240 kHz Reson 8101-ER sonar providing multibeam bathymetry and backscatter data, a TSS/Applanix POS/MV Model 320 which measures position, velocity, attitude and heading, and a Seabird SBE 19 CTD used to measure sound velocity profiles. Specific equipment configurations are documented in metadata from cruises: AHI0402. These metadata can be accessd at: http://www.soest.hawaii.edu/pibhmc/pibhmc_cruise-catalog.htm Time_Period_of_Content: Time_Period_Information: Range of Dates/Times: Beginning_Date: 20040205 Ending_Date: 20040212 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -169.71 East_Bounding_Coordinate: -169.41 North_Bounding_Coordinate: -14.12 South_Bounding_Coordinate: -14.29 Keywords: Theme: Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus Version 1.0 Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography > Backscatter Theme_Keyword: Acoustic Imagery Theme_Keyword: Multibeam Backscatter Theme_Keyword: Backscatter Place: Place_Keyword_Thesaurus: None Place_Keyword: Ofu, Olosega, and Ta'u Islands Place_Keyword: Manu’a Islands Place_Keyword: American Samoa Place_Keyword: South Pacific Place_Keyword: Pacific Ocean Place: Place_Keyword_Thesaurus: CoRIS Place Thesaurus Version 1.0 Place_Keyword: OCEAN BASIN > Pacific Ocean > South Pacific Ocean > Pacific > American Samoa > Ofu, Olosega, and Ta'u Islands Place_Keyword: COUNTRY/TERRITORY > United States of America > American Samoa Access_Constraints: None Use_Constraints: These data are not to be used for navigation purposes. Please acknowledge NOAA and the Joint Institute for Marine and Atmospheric Research (JIMAR) University of Hawaii as the sources of this information. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS) Contact_Address: Address_Type: mailing and physical Address: 1680 East-West Road POST 833 City: Honolulu State_or_Province: HI Postal_Code: 96822 Country: USA Contact_Voice_Telephone: 808-956-5239 Contact_Electronic_Mail_Address: pibhmc@soest.hawaii.edu Contact_Instructions: e-mail preferred Browse_Graphic_File_Name: manua-8101-bs.jpg Browse_Graphic_File_Description: Multibeam Backscatter Browse_Graphic_File_Description: Acoustic Imagery Browse_Graphic_File_Type: JPEG Data_Set_Credit: PIBHMC, CRED, PIFSC, NOAA and JIMAR Native_Data_Set_Environment: GeoTIFF file created using HMRG software in a LINUX environment Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Data are collected for resource management and research purposes and are tested for internal consistency; however, no effort is made to compare these data to external references or to other published data. Logical_Consistency_Report: These data are believed to be logically consistent though no tests were performed Completeness_Report: Complete Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 meters Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: 1 m Range resolution of sonar ~1.25 cm Raw sounding resolution: Variable Vertical accuracy of gridded product: 1% of water depth Lineage: Process_Step: Process_Description: Science Applications International Corporation’s (SAIC) ISS-2000 acquires, processes and records data, provides survey control and underway quality control displays. SAIC’s SABER processing software is used to process the raw soundings, analyze the results, manually edit the sounding data to remove outliers and derive average gridded data values. Additional data acquisition and processing information can be found in the metadata for cruise AHI0402. Hawaii Mapping Research Group (HMRG) processing software was then used to extract values of acoustic intensity from the soundings. HMRG is an organization of scientists, engineers and technicians whose mission is to design, build, and operate tools for mapping the seafloor. HMRG is a group within the School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa. The gsf2bs program (July, 2005) converts the swath bathymetry ping records contained within a GSF (Generic Sensor Format) version 2.02 dataset into bs file format. This is done as follows: (i) position each beam's bottom detect intensity sample at the across-track location of that beam's bathymetry value; (ii) assuming a flat bottom in the near neighborhood of the beam, compute across-track distances for all of the beam's remaining intensity samples based on their temporal relation to the bottom detect sample and the computed average sound velocity for that beam as derived from its range and travel time; (iii) after all of the intensity samples from all beams of a ping have been located in across-track distance, fill the gaps between them as necessary by comparing travel times of beams adjacent to the gap, assigning the position using the adjacent sample closest to nadir, and averaging the interpolated values that fall within a cell. The conversion described above is necessary in order to run HMRG backscatter processing operations on the data, such as filtering to remove noise, and to create netCDF grids, raster images and GeoTIFF's. For more information on the backscatter processing technique see . Software_Used: SAIC ISS-2000 Acquisition Software, v 3.4 SAIC SABER Processing Software, v 3.3.15 Hawaii Mapping Research Group (HMRG) Processing Software GMT Generic Mapping Tools, v 4.1 MB System, v 5.0.7 Process_Date: 20070411 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 6520 for landscape charts Column_Count: 7668 for landscape charts Row_Count: 7668 for portrait charts Column_Count: 6520 for portrait charts Vertical_Count: 1 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 1 Ordinate_Resolution: 1 Planar_Distance_Units: meters Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: -2 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -171 Latitude_of_Projection_Origin: 0 False_Easting: 500000 False_Northing: 0 Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257224 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: mean lower low water Depth_Resolution: 0.01 meters Depth_Distance_Units: meters Depth_Encoding_Method: Attribute values Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Sidescan data within a GSF file are arranged as small sequences of intensity values, one sequence per beam per ping. The intensity values represent the amplitude of echo returns to the sensor and can be related to seabed roughness. Entity_and_Attribute_Detail_Citation: none Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: PIBHMC, CRED, PIFSC, NOAA and JIMAR Contact_Person: Jonathan Weiss Contact_Position: Seafloor Mapping Specialist Contact_Address: Address_Type: mailing and physical address Address: 1680 East-West Road, POST 833 City: Honolulu State_or_Province: Hawaii Postal_Code: 96822 Country: USA Contact_Voice_Telephone: 808-956-5239 Contact_Electronic_Mail_Address: jonathan.weiss@noaa.gov Resource_Description: Downloadable Data Distribution_Liability: These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF, .tif Format_Information_Content: TIFF is a format for storage, transfer, display, and printing of raster images. The TIFF file structure allows both the tag and the image data to be encoded into the same file. GeoTIFF refers to a TIFF file that has geographic data embedded as tags within the TIFF file. The geographic data can be used to position the image in the correct location and geometry on the screen of a geographic information display. Any GIS, CAD, Image Processing, Desktop Mapping and other types of systems using geographic images can read any GeoTiff file. More specifically, files of this type can be added to ArcInfo and ArcView 8.x or higher and may be viewed in the Table of Contents as a new raster layer. Image visualization software that does not use geography as a basis for image placement can view a GeoTIFF image as if there were no geographic information in the TIFF file. For example, GeoTIFF files can be viewed using Windows Picture and Fax viewer.The GeoTIFF format is public domain, non-proprietary. List of Manua Island group 8101 backscatter GeoTIFF files and bounding coordinates: manua-8101-8-01.01.00m.ss.tif W/E/S/N -169.709/-169.454/-14.2496/-14.1304 manua-8101-8-02.01.00m.ss.tif W/E/S/N -169.65/-169.388/-14.2033/-14.1337 manua-8101-8-03.01.00m.ss.tif W/E/S/N -169.65/-169.465/-14.2833/-14.1304 manua-8101-8-04.01.00m.ss.tif W/E/S/N -169.65/-169.454/-14.2917/-14.1337 manua-8101-8-05.01.00m.ss.tif W/E/S/N -169.65/-169.388/-14.2917/-14.1681 manua-8101-8-06.01.00m.ss.tif W/E/S/N -169.709/-169.387/-14.2496/-14.1307 manua-8101-8-07.01.00m.ss.tif W/E/S/N -169.648/-169.388/-14.2275/-14.1304 File_Decompression_Technique: none Transfer_Size: Variable Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://www.soest.hawaii.edu/pibhmc Fees: None Metadata_Reference_Information: Metadata_Date: 20070503 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS) Contact_Address: Address_Type: mailing and physical Address: 1680 East-West Road POST 833 City: Honolulu State_or_Province: HI Postal_Code: 96822 Country: USA Contact_Voice_Telephone: 808-956-5239 Contact_Electronic_Mail_Address: pibhmc@soest.hawaii.edu Contact_Instructions: e-mail preferred Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: Universal Time Metadata_Access_Constraints: None Metadata_Use_Constraints: None