Identification_Information: Citation: Citation_Information: Originator: NOAA Pacific Island Fisheries Science Center, Coral Reef Ecosystem Division (CRED), Pacific Islands Benthic Habitat Maping Center Publication_Date: August 2005 Title: Acoustic imagery extracted from gridded bathymetry of the Commonwealth of Northern Mariana Islands (CNMI) and the U.S. Territory of Guam Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: http://www.soest.hawaii.edu/pibhmc Online_Linkage: http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi.htm Description: Abstract: Backscatter extracted from gridded bathymetry of the banktops and shelf environments of the Commonwealth of Northern Mariana Islands (CNMI) and the northest portion of the U.S. Territory of Guam. Purpose: This GeoTIFF of acoustic imagery was created using data gathered from multibeam soundings for use as a planning and reference document. Refer to supplemental information for description of instrument and survey. Supplemental_Information: 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 bathymetry and imagery 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. Equipment serial numbers and software versions are as follows: RESON 8101-ER multibeam echosounder DOC inventory #: CD0000537418 Firmware, dry: 8101-2.07-2D4D Firmware, wet: 8101-1.06-2F6B POS/MV Model 320, version 3 DOC inventory #: CD0000476647 PCS serial #: 474 IMU serial #: 203 Controller software: v 1.0.5.0 Seabird SBE19 CTD: Serial #: 3029 R/V AHI Lever Arm Distances and Alignment Offsets The R/V AHI Reference Point (RP) is defined to be the intersection of the vessel's centerline, the cabin deck and the bulkhead immediately aft of the transducer. This is marked by a punch in the deck weld at that location. Positive X means the point is forward of the RP, positive Y means the point is to starboard of the RP, positive Z means the point is below the RP. The loaded waterline is defined as the intersection of the vessel’s performance wing with the hull at the transom. Antenna Baseline Distance, m: 1.229 Transducer depth below waterline, m 0.62 RP to IMU 0.80 0.00 0.08 RP to Primary GPS Antenna -3.55 -0.61 -1.88 RP to Vessel 0.16 0.00 0.77 RP to Sensor 1(MB transducer) 0.16 0.00 0.77 RP to Sensor 2 0 0 0 RP to Aux. GPS Antenna 0 0 0 RP to Heave lever arm(deg) -0.67 0.00 0.00 IMU rotation Ref. Frame, deg 0 0 0 Sensor 1 rotation Ref. Frame, deg 0 0 0 Sensor 2 rotation Ref. Frame, deg 0 0 0 Roll offset: +0.5 deg Pitch offset: 0.0 deg Gyro offset: 0.0 deg Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20030823 Ending_Date: 20030912 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: 144.84 East_Bounding_Coordinate: 145.894 North_Bounding_Coordinate: 15.4571 South_Bounding_Coordinate: 13.6167 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Acoustic Imagery Theme_Keyword: Backscatter Theme_Keyword: Sidescan Place: Place_Keyword_Thesaurus: None Place_Keyword: Commonwealth of the Northern Mariana Islands Place_Keyword: U.S. Territory of Guam Access_Constraints: None Use_Constraints: These data are not to be used for navigation purposes. Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as the source 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: Browse_Graphic_File_Name: ahi0304-8-xx.01.00m.ss.tif Browse_Graphic_File_Description: Acoustic Imagery Browse_Graphic_File_Description: Backscatter Browse_Graphic_File_Description: Sidescan Browse_Graphic_File_Type: GeoTIFF Data_Set_Credit: Pacific Islands Benthic Habitat Mapping Center, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA 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: Unspecified Completeness_Report: Complete Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal positioning system: GPS SPS Horizontal position accuracy: 1.0 meters Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Range resolution of sonar ~ 1.25 cm Raw sounding resolution: 1 cm Vertical accuracy of gridded product ~ 1 meter 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. The data have been corrected for observed tides from Guam tide gauge 1630000 with a time corrector of 18 minutes and a tide height multiplier of 0.94 using SABER postprocessing software. The data were also recorrected for observed sound velocities in postprocessing. 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 gsf2mr program (July, 2003) converts the swath bathymetry ping records contained within a GSF (Generic Sensor Format) version 2.02 dataset into mr1file 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 interpolation. 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 geotiffs. GMT was then used to reformat the acoustic imagery when necessary. Interactive Visualization System’s Fledermaus, ESRI ArcGIS, and RSI ENVI were used for viewing results and creating browse objects. Software used: SAIC ISS-2000 Acquisition Software, v 3.4 (20030610) SAIC SABER Processing Software, v 2.0.2 (20030610) Hawaii Mapping Research Group (HMRG) Processing Software GMT Generic Mapping Tools, v 3.4.2 (20021002) Process_Date: 20050512 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 6520 Column_Count: 7668 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: 55 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 9.9996 Longitude_of_Central_Meridian: 147 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: 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 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 metadata 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 without geographic information.The GeoTIFF format is public domain, non-proprietary. List of CNMI and Guam backscatter GeoTIFF files: ahi0304-8-01.01.00m.ss.tif ahi0304-8-02.01.00m.ss.tif ahi0304-8-03.01.00m.ss.tif ahi0304-8-04.01.00m.ss.tif ahi0304-8-05.01.00m.ss.tif ahi0304-8-06.01.00m.ss.tif ahi0304-8-07.01.00m.ss.tif ahi0304-8-08.01.00m.ss.tif ahi0304-8-09.01.00m.ss.tif ahi0304-8-10.01.00m.ss.tif ahi0304-8-11.01.00m.ss.tif ahi0304-8-12.01.00m.ss.tif ahi0304-8-13.01.00m.ss.tif ahi0304-8-14.01.00m.ss.tif ahi0304-8-15.01.00m.ss.tif ahi0304-8-16.01.00m.ss.tif ahi0304-8-17.01.00m.ss.tif ahi0304-8-18.01.00m.ss.tif ahi0304-8-19.01.00m.ss.tif ahi0304-8-20.01.00m.ss.tif ahi0304-8-21.01.00m.ss.tif ahi0304-8-22.01.00m.ss.tif File_Decompression_Technique: none Transfer_Size: variable Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: www..soest.hawaii.edu/pibhmc/ Fees: None Metadata_Reference_Information: Metadata_Date: 20050828 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: local time Metadata_Access_Constraints: None Metadata_Use_Constraints: None