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)
20070701
CRED Reson 8101 multibeam backscatter data of Johnston Island, Pacific Remote Island Areas, Central Pacific in netCDF format
digital data
http://www.soest.hawaii.edu/pibhmc/cms/data-by-location/pacific-remote-island-area/johnston-atoll/johnston-atoll-backscatter/
Multibeam backscatter imagery extracted from gridded bathymetry of the lagoon, shelf, and slope environments of Palmyra
Atoll, Pacific Island Areas, Central Pacific. These data provide coverage between 20 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 1 m grid
cell size Reson 8101 multibeam backscatter data only.
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.
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: AHI0601. These metadata can be accessd at:
http://www.soest.hawaii.edu/pibhmc/cms/cruise-catalog/.
20060118
20060124
ground condition
As needed
-169.58
-169.338
16.799
16.6495
NCEI Geoportal FilterCoRIS_Metadata
CRCP Project
Benthic Habitat Mapping and Characterization - American Samoa and PRIA
2034
Benthic Habitat Mapping and Characterization - American Samoa and PRIA
1084-06
none
EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography > Backscatter
Acoustic Imagery
Multibeam Backscatter
Backscatter
CoRIS Theme Thesaurus
EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Backscatter
ISO 19115 Topic Category
oceans
014
elevation
006
CoRIS Discovery Thesaurus
Geographic Information > Backscatter
CoRIS Place Thesaurus
OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Johnston Atoll > Johnston Atoll (16N169W0001)
COUNTRY/TERRITORY > United States of America > USA Minor Outlying Islands > Johnston Atoll (16N169W0001)
None
Johnston Atoll
Pacific Remote Island Areas
Central Pacific
Pacific Ocean
none
OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Pacific Remote Island Areas > Johnston Atoll
COUNTRY/TERRITORY > United States of America > Pacific Remote Island Areas
CoRIS Region
PRIA
None
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.
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)
mailing and physical address
NOAA IRC
NMFS/PIFSC/CRED
1845 WASP Blvd., Building 176
Honolulu
HI
96818
808 725-5360
808 725-5429
nmfs.pic.credinfo@noaa.gov
e-mail preferred
http://www.soest.hawaii.edu/pibhmc/PRIAs_images/johnston-bs_440.jpg
Multibeam Backscatter, Acoustic Imagery
JPEG
http://www.soest.hawaii.edu/pibhmc/PRIAs_images/johnston-8101-bs-boxes_440.jpg
Multibeam Backscatter, Acoustic Imagery
JPEG
PIBHMC, CRED, PIFSC, NOAA and JIMAR
Not applicable
Unclassified
Not applicable
netCDF file created using HMRG software in a LINUX environment
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.
These data are believed to be logically consistent
though no tests were performed
Complete
Horizontal positioning system: GPS (SPS)
Horizontal position accuracy: 25 meters
1 m
Range resolution of sonar ~1.25 cm
Raw sounding resolution: Variable
Vertical accuracy of gridded product: 1% of water depth
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 AHI0601.
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
<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
20061127
Raster
Grid Cell
6520
7668
1
Universal Transverse Mercator
2
0.9996
-171
0
500000
0
Row and Column
1
1
meters
D_WGS_1984
WGS_1984
6378137.000000
298.257224
mean lower low water
0.01
meters
Attribute Values
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.
none
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)
mailing and physical address
NOAA IRC
NMFS/PIFSC/CRED
1845 WASP Blvd., Building 176
Honolulu
HI
96818
808 725-5360
808 725-5429
nmfs.pic.credinfo@noaa.gov
e-mail preferred
Downloadable Data
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.
netCDF, .grd
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). 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 Island Reson 8101 backscatter netCDF files and bounding coordinates:
johnston-8101-8-01.01.00m.ss.grd
W/E/S/N -169.58/-169.508/16.6495/16.709
johnston-8101-8-02.01.00m.ss.grd
W/E/S/N -169.58/-169.518/16.6996/16.769
johnston-8101-8-03.01.00m.ss.grd
W/E/S/N -169.56/-169.488/16.7395/16.799
johnston-8101-8-04.01.00m.ss.grd
W/E/S/N -169.5/-169.428/16.7395/16.799
johnston-8101-8-05.01.00m.ss.grd
W/E/S/N -169.44/-169.378/16.7195/16.789
johnston-8101-8-06.01.00m.ss.grd
W/E/S/N -169.4/-169.338/16.6695/16.7394
johnston-8101-8-07.01.00m.ss.grd
W/E/S/N -169.45/-169.378/16.6495/16.709
johnston-8101-8-08.01.00m.ss.grd
W/E/S/N -169.52/-169.448/16.6495/16.709
none
http://www.soest.hawaii.edu/pibhmc/cms/data-by-location/pacific-remote-island-area/johnston-atoll/johnston-atoll-backscatter/
None
20190605
20090504
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)
mailing and physical address
NOAA IRC
NMFS/PIFSC/CRED
1845 WASP Blvd., Building 176
Honolulu
HI
96818
808 725-5360
808 725-5429
nmfs.pic.credinfo@noaa.gov
e-mail preferred
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
Universal Time
None
None
20090504012518
None
20060118
20060124
https://www.coris.noaa.gov/metadata/records/html/cred_backscatter_johnston_8101_grd.html
4042