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 Midway 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,
Midway 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 Midway Island. Refer to supplemental information for description of
instrument and survey.
The Midway Islands, located at 28.2 N, 177.4W, are enclosed in the classically shaped Midway
Atoll. Within the reef are three islands; Sand Island and Eastern Island were extensively modified during the U.S.
Navy's occupation of the atoll. The atoll and banks include 223 sq. km of area with depths less than 100 m. The
area is now the Midway Atoll National Wildlife Refuge which is under jurisdiction of the U.S. Fish and Wildlife Service.
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 PIFSC
1125B Ala Moana Blvd
Honolulu, HI 98614
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 MID04001.
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 "MID04001a.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, "MID04001a.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.
20041004
20041005
ground condition
As needed
-177.48372
-177.40412
28.2854
28.1745
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 > Midway Atoll (28N177W0001)
COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Midway Atoll (28N177W0001)
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
1125B Ala Moana Blvd.
Honolulu
HI
96814
(808) 983-3776
(808) 983-2902
pibhmc@soest.hawaii.edu
e-mail preferred
http://data.nodc.noaa.gov/coris/data/NOAA/nmfs/pifsc/cred/TOADbrowse/TOAD_MID_92dpi.jpg
Midway Atoll, NWHI: TOAD Tows and Multibeam Bathymetry
JPEG
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
1125B Ala Moana Blvd.
Honolulu
HI
96814
(808) 983-3776
(808) 983-2902
pibhmc@soest.hawaii.edu
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:
MID04001.glo
MID04002a.glo
MID04003.glo
MID04004aa.glo
MID04005.glo
MID04006.glo
MID04007.glo
MID04008.glo
MID04009a.glo
MID04010a.glo
CD-ROM
ISO 9660
mini digital video
List of Video tapes:
MID04001-002, Mini DV, Master
MID04003-004, Mini DV, Master
MID04005, Mini DV, Master
MID04006-007, Mini DV, Master
MID04008-009, Mini DV, Master
MID04010, Mini DV, Master
MID04001-002, Mini DV, Backup
MID04003-004, Mini DV, Backup
MID04005, Mini DV, Backup
MID04006-007, Mini DV, Backup
MID04008-009, Mini DV, Backup
MID04010, Mini DV, Backup
Video cassette tape
Mini DV
None
20121217
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
1125B Ala Moana Blvd.
Honolulu
HI
96814
(808) 983-3776
(808) 983-2902
pibhmc@soest.hawaii.edu
e-mail preferred
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
20080502065232
None
20041004
20041005
http://www.coris.noaa.gov/metadata/records/html/cred_toad_midway_hi0401_2004.html
1487