Identification_Information: Citation: Citation_Information: Originator: Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Publication_Date: 20070824 Title: CRED Simrad em300 multibeam backscatter data of Johnston Atoll, Pacific Remote Island Areas, Central Pacific in GeoTIFF format Geospatial_Data_Presentation_Form: digital data Online_Linkage: http://www.soest.hawaii.edu/pibhmc/cms/data-by-location/pacific-remote-island-area/johnston-atoll/johnston-atoll-backscatter/ Description: Abstract: Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Johnston Island, Pacific Island Areas, Central Pacific. These data provide coverage between 10 and 5000 meters. The backscatter dataset includes data collected using Simrad EM300 and Reson 8101 multibeam sonars. The sonars frequencies are 30 kHz and 240 kHz respectively and the backscatter data from each sonar are processed and gridded separately. These metadata are for the 5 m grid cell size Simrad em300 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 NOAA Ship Hi'ialakai, a 218' United States National Oceanographic and Atmospheric Administration research ship. The NOAA Ship Hi'ialakai's survey sensors include a 30 kHz Simrad EM300 sonar and a 300 kHz Simrad EM3002d sonar, which provide bathymetry and imagery data, a TSS/Applanix POS/MV Model 320, which measures position, velocity, attitude and heading, and a Seabird SBE 9/11 plus CTD used to measure sound velocity profiles. Specific equipment configurations are documented in metadata from cruises: HI0601. These metadata can be accessed at: http://www.soest.hawaii.edu/pibhmc/cms/cruise-catalog/. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20060118 Ending_Date: 20060124 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -169.7 East_Bounding_Coordinate: -169.264 North_Bounding_Coordinate: 16.9141 South_Bounding_Coordinate: 16.5583 Keywords: Theme: Theme_Keyword_Thesaurus: NCEI Geoportal Filter Theme_Keyword: CoRIS_Metadata Theme: Theme_Keyword_Thesaurus: CRCP Project Theme_Keyword: Benthic Habitat Mapping and Characterization - American Samoa and PRIA Theme_Keyword: 2034 Theme_Keyword: Benthic Habitat Mapping and Characterization - American Samoa and PRIA Theme_Keyword: 1084-06 Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography > Backscatter Theme_Keyword: Acoustic Imagery Theme_Keyword: Multibeam Backscatter Theme_Keyword: Backscatter Theme: Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Backscatter Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: 014 Theme_Keyword: elevation Theme_Keyword: 006 Theme: Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus Theme_Keyword: Geographic Information > Backscatter Place: Place_Keyword_Thesaurus: CoRIS Place Thesaurus Place_Keyword: OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Johnston Atoll > Johnston Atoll (16N169W0001) Place_Keyword: COUNTRY/TERRITORY > United States of America > USA Minor Outlying Islands > Johnston Atoll (16N169W0001) Place: Place_Keyword_Thesaurus: None Place_Keyword: Johnston Atoll Place_Keyword: Pacific Remote Island Areas Place_Keyword: Central Pacific Place_Keyword: Pacific Ocean Place: Place_Keyword_Thesaurus: none Place_Keyword: OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Pacific Remote Island Areas > Johnston Atoll Place_Keyword: COUNTRY/TERRITORY > United States of America > Pacific Remote Island Areas Place: Place_Keyword_Thesaurus: CoRIS Region Place_Keyword: PRIA 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. 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), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Contact_Address: Address_Type: mailing and physical address Address: NOAA IRC Address: NMFS/PIFSC/CRED Address: 1845 WASP Blvd., Building 176 City: Honolulu State_or_Province: HI Postal_Code: 96818 Contact_Voice_Telephone: 808 725-5360 Contact_Facsimile_Telephone: 808 725-5429 Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov Contact_Instructions: e-mail preferred Browse_Graphic: Browse_Graphic_File_Name: http://www.soest.hawaii.edu/pibhmc/PRIAs_images/johnston-bs_440.jpg Browse_Graphic_File_Description: Multibeam Backscatter, Acoustic Imagery Browse_Graphic_File_Type: JPEG Browse_Graphic: Browse_Graphic_File_Name: http://www.soest.hawaii.edu/pibhmc/PRIAs_images/johnston-em300-bs-boxes_440.jpg Browse_Graphic_File_Description: Multibeam Backscatter, Acoustic Imagery Browse_Graphic_File_Type: JPEG Data_Set_Credit: PIBHMC, CRED, PIFSC, NOAA and JIMAR Security_Information: Security_Classification_System: Not applicable Security_Classification: Unclassified Security_Handling_Description: Not applicable 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 cruises HI0601 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: 20070428 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 4706 Column_Count: 4792 Vertical_Count: 1 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: 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 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: Row and Column Coordinate_Representation: Abscissa_Resolution: 5 Ordinate_Resolution: 5 Planar_Distance_Units: meters 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 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), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Contact_Address: Address_Type: mailing and physical address Address: NOAA IRC Address: NMFS/PIFSC/CRED Address: 1845 WASP Blvd., Building 176 City: Honolulu State_or_Province: HI Postal_Code: 96818 Contact_Voice_Telephone: 808 725-5360 Contact_Facsimile_Telephone: 808 725-5429 Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov 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 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 Palmyra Atoll Simrad EM300 backscatter GeoTIFF files and bounding coordinates: johnston-em300-25-01.05.00m.ss.tif W/E/S/N -169.7/-169.474/16.5585/16.7442 johnston-em300-25-02.05.00m.ss.tif W/E/S/N -169.49/-169.264/16.5583/16.7441 johnston-em300-25-03.05.00m.ss.tif W/E/S/N -169.7/-169.474/16.7285/16.9142 johnston-em300-25-04.05.00m.ss.tif W/E/S/N -169.49/-169.264/16.7282/16.9141 File_Decompression_Technique: none Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://www.soest.hawaii.edu/pibhmc/cms/data-by-location/pacific-remote-island-area/johnston-atoll/johnston-atoll-backscatter/ Fees: None Metadata_Reference_Information: Metadata_Date: 20190605 Metadata_Review_Date: 20090505 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), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Contact_Address: Address_Type: mailing and physical address Address: NOAA IRC Address: NMFS/PIFSC/CRED Address: 1845 WASP Blvd., Building 176 City: Honolulu State_or_Province: HI Postal_Code: 96818 Contact_Voice_Telephone: 808 725-5360 Contact_Facsimile_Telephone: 808 725-5429 Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov 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 CoRIS: CoRIS_ID: 20090505051217 CoRIS_Children: None CoRIS_Beginning_Date: 20060118 CoRIS_Ending_Date: 20060124 CoRIS_Metadata_Link: https://www.coris.noaa.gov/metadata/records/html/cred_backscatter_johnston_em300_tif.html CoRIS_Tracking_ID: 4057