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)
200606
CRED Optical Validation Data at Necker Island, 2004, to Support Benthic Habitat Mapping
Video imagery, track line navigation files, and log sheets
http://www.soest.hawaii.edu/pibhmc/
Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled
equipped with an underwater digital video camera and lights. Data were collected at the Northwestern Hawaiian Islands,
Necker Island to support Benthic Habitat Mapping efforts.
This data provides optical observations that will be correlated with bathymetry and acoustic backscatter imagery
to develop a benthic habitat map of Necker Island. Refer to supplemental information for description of instrument
and survey.
Necker Island is a small basalt island located at 23.6N, 164.7W. The total land area is 0.16 sq. km
but its surrounding shelf is extensive with 1,538 sq. km of coral habitat less than 100 m.
Optical validation data were collected using the Tethered Optical Assessment Device (TOAD), a sled equipped with
underwater video camera and lights. These data are used to provide ground-truth validation that for benthic habitat
maps based on multibeam echosounder surveys. Camera sled deployments were conducted at night, usually between 1800
and midnight. Each tow was usually limited to 20 minutes of bottom time at a given location in order to allow for
more tows to be conducted in a given work area and thus increase the spatial distribution of the observations. The
camera sled was deployed from lower arm of the starboard J-frame on the NOAA Ship Hi'ialakai. At each station the
ship was positioned with the wind on the starboard side and drifted downwind; occasional light turns were applied to
the ship's screws if necessary to reduce the ship's motion. The TOAD was lowered slowly to the bottom by the deck
crew. The operator monitored a live video feed from the camera and began recording data on two video tape recorders.
When the camera reached bottom the deck crew was notified by radio to stop lowering. The operator continued to
monitor the vehicle and provided commands to raise or lower it to keep the camera just above the bottom.
Equipment Description: The TOAD was deployed from the lower arm of the vessel's J-frame. The TOAD is a camera sled
based on the Guildline MiniBat model 8820 tow body. The frame has been extensively modified from its original configuration
and was configured with a single ROS model 54-00100-13 color underwater video camera and two 500 W DeepSea Power &
Light model 710-0400601 underwater lights mounted on the original sled frame. The MiniBat pressure sensor and wing
controller was also mounted on the frame but no wings were installed. Cable between the sled and the surface consisted
of an underwater electrical cable (cable 1, blue in color) with a separate load-bearing line to support the sled
frame. The electrical cable was clipped to the line at regular intervals upon deployment and removed upon recovery.
The load-bearing line was led to the starboard capstan on the aft deck. All TOAD surface components were located in
the Dry Lab in an equipment rack on the after bulkhead. After operations began we learned that the sled's pressure
sensor was not working.
Name & address of person collecting data:
John Rooney
NOAA IRC
NMFS/PIFSC/CRED
1845 WASP Blvd., Building 176
Honolulu, HI 96818
Data Files: Video data were recorded on two video tape recorders. The position of the camera sled was recorded using
Guildline MiniBat In-Tow data acquisition software.
File naming convention: Each tow is given a name consisting of a 3-letter designator for the island area followed by
a two-digit year and three-digit tow number. For example, during HI0401 the first tow was called NEC04001. Video
tape labels, the navigation files (*.glo) and paper log forms are all annotated with the tow name. If the navigation
file is edited during processing the file name has a suffix "a" added. For example, one of the navigation data files
is named "NEC04001a.glo". Metadata were extracted from the navigation data and recorded to a file with the same name
as the navigation file except that a file type of ".met" was appended; for example, "NEC04001a.glo.met"
Time Correlation: All times are based on UTC. Two clocks were set manually synchronized prior to starting data collection;
the clock in the video character generator that was used to annotate the video tape and the TOAD data acquisition
computer clock was used to annotate the navigation (*.glo) files. These clocks were set to UTC at the beginning of
each evening's operations and then compared to one another prior to (and during) each tow. There were problems maintaining
synchronization of the TOAD computer clock during this cruise. See the problems section for a description. (Problems
with data could be described here.)
Resource Description: Digital video images that are geo-referenced to navigation files.
20041014
ground condition
As needed
-164.81547
-164.75106
23.6226
23.50706
NCEI Geoportal FilterCoRIS_MetadataCRCP ProjectBenthic Habitat Mapping and Characterization - Northwestern and Main Hawaiian Islands1217
CoRIS Theme Thesaurus
EARTH SCIENCE > Biosphere > Aquatic Habitat > Benthic Habitat
EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping
EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Photographic Analysis > Videography
None
Tethered Optical Assessment Device (TOAD)
Underwater video
HI0401
CoRIS Discovery Thesaurus
Visual Images > Habitats
ISO 19115 Topic Category
environment
biota
CoRIS Place Thesaurus
OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands > Necker Island (23N164W0001)
COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Necker Island (23N164W0001)
OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands (28N178W0000)
COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Northwestern Hawaiian Islands (28N178W0000)
CoRIS Region
NWHI
None
Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as
the source 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)
John Rooney
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
Benthic Habitat Mapping Group, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science
Center (PIFSC), NOAA
Not applicable
Unclassified
Not applicable
Unspecified
Complete
The horizontal position accuracy for the camera sled position is 100 meters.
There are three primary sources of this error. The ship's positioning is based on GPS SPS, often called standalone
or non-differential GPS positioning. SPS has a measured accuracy of under 5 meters. The position of the GPS antenna
is used; no attempt is made to translocate this position to that of the tow block from which the camera is deployed.
The difference between the tow block and the antenna is about 14 meters. The camera sled position is based a layback
calculation that use ship's course, the amount of cable out and the camera sled depth to develop an estimate of the
camera sled position. The amount of cable deployed is manually entered by the operator during a given camera tow.
After a tow was completed the video tape data was reviewed by spot-checking the master and backup
tape to verify that data were recorded. Navigation data were copied from the acquisition computer to the data archive.
A metadata extractor (gloFilter.py, version 3/06) was run to summarize the navigation data and test for errors. If
errors were detected they were corrected or flagged as appropriate and a new data file was made. This file's header
was updated to document what type of processing occurred. A metadata file was recorded in the data archive in the
same location as the navigation data. Processed navigation data were then read into ArcView 3.2 shapefiles using an
ArcView Avenue script named "TOAD.Import.Playback", version 9/25/01, written by Ronald Hoeke.
20041015
0.0001
0.0001
Decimal Degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
No correction
0.1
meters
Attribute Values
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)
John Rooney
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
Offline 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.
ASCII
Each comma-delimited record contains year, day of year, time, latitude, longitude,
velocity north and east, water column depth, vehicle depth, layback, and wing angle. For this data set the fields
for vehicle depth and wing angle do not contain useful data.
List of navigation files:
NEC04001.glo
NEC04002a.glo
NEC04003a.glo
NEC04004a.glo
NEC04005a.glo
NEC04006a.glo
CD-ROM
ISO 9660
mini digital video
List of Video tapes:
NEC04001-002, Mini DV, Master
NEC04003-004, Mini DV, Master
NEC04005-006, Mini DV, Master
NEC04001-002, Mini DV, Backup
NEC04003-004, Mini DV, Backup
NEC04005-006, Mini DV, Backup
Video cassette tape
Mini DV
None
20200329
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)
CRED Data Management Team
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 Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
20080502065315
None
20041014
20041014
https://www.coris.noaa.gov/metadata/records/html/cred_toad_necker_hi0401_2004.html
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