Identification_Information: Citation: Citation_Information: Originator: Benthic Habitat Mapping Group, CRED, PIFSC, NOAA Publication_Date: 20100701 Title: Gridded bathymetry of Swains Island, American Samoa Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: http://www.soest.hawaii.edu/pibhmc Online_Linkage: http://www.soest.hawaii.edu/pibhmc/pibhmc_amsamoa_swains_bathy.htm Description: Abstract: Gridded bathymetry (40 m cell size) of the slope environment of Swains Island, American Samoa. Almost complete bottom coverage was achieved in depths between 7 and 4800 m. The multibeam data are from the Simrad EM300 system aboard the NOAA Ship Hi'ialakai, and the Reson 8101ER system aboard the R/V AHI and were collected from 10th - 13th February 2006. Purpose: The data were collected in support of Coral Reef Conservation Program goals to map all shallow (0-30 m) coral reefs in US Pacific waters and priority moderate (> 30 m) depth areas by 2009. The data are being used to provide bathymetric and backscatter data for previously unmapped areas; in support of ecosystem management requirements for benthic habitat mapping and location of Essential Fish Habitat; and to study the geologic features of the area. Supplemental_Information: Data were collected aboard the NOAA Ship Hiialakai, a 218’ United States National Oceanographic and Atmospheric Administration research ship. The NOAA Ship Hiialakai'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. Sensor configuration for the Hi'ialakai for cruise HI-06-02 is documented in the cruise/multibeam metadata file HI0602_MB_Metadata.txt. Data were also 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. Sensor configuration for the AHI for cruise AHI-06-02 is documented in the cruise/multibeam metadata file AHI0602_MB_Metadata.txt. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20040210 Ending_Date: 20060313 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -171.218733 East_Bounding_Coordinate: -171.93808 North_Bounding_Coordinate: -10.934991 South_Bounding_Coordinate: -11.188662 Keywords: Theme: Theme_Keyword_Thesaurus: CoRIS Theme Keyword Thesaurus Theme_Keyword: EARTH SCIENCE > Biosphere > Aquatic Habitat > Reef Habitat > Description Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Bathymetry Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Water Depth Place: Place_Keyword_Thesaurus: CoRIS Place Thesaurus Place_Keyword: OCEAN BASIN > Pacific Ocean > American Samoa > Swains Atoll (11S171W0001) Place_Keyword: COUNTRY/TERRITORY > United States of America > American Samoa > American Samoa > Swains Atoll (11S171W0001) 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 and the Pacific Islands Benthic Habitat Mapping Center, School of Ocean and Earth Science and Technology, University of Hawaii as the sources of this information. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Benthic Habitat Mapping Group, Coral Reef Ecosystem Division, PIFSC,NOAA Contact_Person: John Rooney Contact_Address: Address_Type: mailing and physical address Address: 1125B Ala Moana Blvd City: Honolulu State_or_Province: HI Postal_Code: 96814 Country: USA Contact_Voice_Telephone: 808-956-5239 Contact_Electronic_Mail_Address: john.rooney@noaa.gov Browse_Graphic: Browse_Graphic_File_Name: ftp://ftp.soest.hawaii.edu/pibhmc/website/data/amsamoa/bathymetry/Swains_40m.jpg Browse_Graphic_File_Description: Gridded Bathymetry Browse_Graphic_File_Type: jpg Data_Set_Credit: Benthic Habitat Mapping Group, 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: 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 C/A Horizontal position accuracy: 25 meters Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Range resolution of sonar: varies with depth Raw sounding resolution: varies with depth Vertical accuracy of gridded product ~ 1% of water depth Lineage: Process_Step: Process_Description: Multibeam swath files are acquired in the Generic Sensor Format (GSF) and are edited on a swath by swath basis using SAIC's SABER editing software. The edited swath files are then combined into a Pure File Magic (PFM) format in SABER and area based editing is performed. The edited PFM is then exported as X,Y,Z. The resulting X,Y,Z data are then gridded using nearneighbor, a Generic Mapping Tools (GMT) algorithm that reads arbitrarily located X,Y,Z and assigns an average value to each grid node that has one or more points within a 200 m radius centered on the node and outputs a netCDF grid file. GMT is an open source collection of tools for manipulating geographic data sets. Grid nodes with more than one value are set to the average value and unconstrained nodes are set to NaN. Finally, the netCDF grid is clipped at a depth that minimizes data gaps for the specified grid cell size and then converted to an ArcGIS ASCII file format using LINUX/UNIX commands in combination with GMT. Additional information about GMT can be found at: www.soest.hawaii.edu/gmt and additional information about the multibeam data processing is recorded in the cruise metadata report AHI0602_MB_Metadata.txt Process_Date: 20100607 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 699 Column_Count: 766 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: 40 Ordinate_Resolution: 40 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: 1000000 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: Depth values are real values based on the average of the soundings that fell within the extracted grid cells. The number of soundings per grid cell range from >1000 soundings in shallow depths to as few as 20 soundings in deeper areas. A total error budget for this survey has not been developed. Therefore, the accuracy of depth measurements should be considered to be within 1 per cent of water depth. Entity_and_Attribute_Detail_Citation: none Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: PIBHMC, CRED, PIFSC, NOAA and JIMAR Contact_Person: John Rooney Contact_Position: Geomorphologist 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: 808-956-9729 Contact_Electronic_Mail_Address: John.Rooney@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: netCDF Format_Information_Content: Binary netCDF Grid: This file is formatted as a 2-D binary netCDF grid file. This is the default grid file format used by GMT (Generic Mapping Tools), which created this file. More information can be be located at and File_Decompression_Technique: Zip file Transfer_Size: 2.1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://www.soest.hawaii.edu/pibhmc/pibhmc_amsamoa_swains_bathy.htm Fees: None Metadata_Reference_Information: Metadata_Date: 20100701 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Sciences Center, NOAA National Marine Fisheries Service Contact_Person: CRED Data Management Team Contact_Address: Address_Type: mailing and physical address Address: 1125 'B' Ala Moana Blvd City: Honolulu State_or_Province: Hawaii Postal_Code: 96814 Country: USA Contact_Voice_Telephone: 808-983-3722 Contact_Facsimile_Telephone: 808-983-3730 Contact_Electronic_Mail_Address: haiying.wang@noaa.gov 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