CRED Simrad em3002d multibeam backscatter data of Johnston Atoll, Pacific Remote Island Areas, Central Pacific in netCDF format

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Metadata:


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: 20070701
Title:
CRED Simrad em3002d multibeam backscatter data of Johnston Atoll, Pacific Remote Island Areas, Central Pacific in netCDF 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 20 and 5000 meters. The backscatter dataset includes data collected using Simrad EM3002d and Reson 8101 multibeam sonars. The sonars frequencies are 300 kHz and 240 kHz respectively and the backscatter data from each sonar are processed and gridded separately. These metadata are for the 1 m grid cell size Simrad em3002d multibeam backscatter data only.
Purpose:
The netCDF grids 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: 20060120
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -169.535
East_Bounding_Coordinate: -169.333
North_Bounding_Coordinate: 16.744
South_Bounding_Coordinate: 16.6495
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:
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.
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-em3002d-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: netCDF 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 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. In addition to the standard processing routines applied to Simrad em3002d backscatter data, an additional gain correction was applied to the data to address a systematic mismatch in received acoustic signal strength between the port and starboard sonar heads. Data with a lower strength were multiplied by an empirically determined scaling factor. For more information on the backscatter processing technique see <http://www.soest.hawaii.edu/pibhmc/pibhmc_documentation.htm>. 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: 6520
Column_Count: 7668
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: 1
Ordinate_Resolution: 1
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: netCDF, .grd
Format_Information_Content:
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). The file was created by the HMRG sofware program bsovl. More information about netCDF files can be found at at http://www.soest.hawaii.edu/gmt/ and http://www.unidata.ucar.edu/software/netcdf/. List of Johnston Simrad em3002d backscatter netCDF files and bounding coordinates: johnston-em3002d-8-01.01.00m.ss.grd W/E/S/N -169.535/-169.463/16.6495/16.709 johnston-em3002d-8-02.01.00m.ss.grd W/E/S/N -169.405/-169.333/16.6844/16.744
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_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: 20090504013154
CoRIS_Children: None
CoRIS_Beginning_Date: 20060118
CoRIS_Ending_Date: 20060120
CoRIS_Metadata_Link:
https://www.coris.noaa.gov/metadata/records/html/cred_backscatter_johnston_em3000d_grd.html
CoRIS_Tracking_ID: 4044

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