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)
200509
CRED Optical Validation Data at the island of Tutuila in American Samoa, 2002 to Support Benthic Habitat Mapping
Video and photo 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 Tutuila, American Samoa to
support Benthic Habitat Mapping efforts during NOAA Ship Townsend Cromwell cruise TC0201.
These data provide optical observations that will be correlated with bathymetry and acoustic backscatter
imagery to develop a benthic habitat map of Tutuila. Refer to supplemental information for description of instrument and survey.
Tutuila is the largest of seven islands in American Samoa at 142.3 sq. km. Volcanic in origin, it reaches a height
of 653m at Matafao Peak. Tutuila is centered at 14.30?N, 169.75?W, has 101.3 km of coastline and an estimated 36.2
sq. km of reef area. The port of Pago Pago is a collapsed crater and is one of the largest natural ports in the
Pacific. Pago Pago contains a tuna cannery which is a hub of a large purse-seining tuna fishing fleet. The cannery
outputs large amounts of nutrients as byproduct into the waters of Pago Pago harbor. The human population of Tutuila
in 1990 was 45,043. It is considered a high island and contributes significant nutrient and sediment runoff to
coastal waters. Tutuila's waters are protected by the 0.7 sq. km Fagatele Bay National Marine Sanctuary, as well as
by the National Park of American Samoa, which covers the north-central part of the island and approximately 5 sq. km of coastline.
Optical validation data were collected using the Tethered Optical Assessment Device (TOAD), a sled equipped with
underwater video camera, still camera, and lights. These data are used to provide ground-truth validation for
benthic habitat maps based on multibeam echosounder surveys. Camera sled deployments were conducted at night,
usually between 1800 and midnight. The TOAD was deployed from a pot hauler mounted on the starboard side of the
fantail on NOAA Ship Townsend Cromwell. It was lowered slowly to the bottom by the deck crew with the use of a capstan.
The TOAD 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 TOAD was a MiniBat 8820
unit manufactured by Guideline, and was towed by the ship at 1-2 knots while remotely guided from the ship using
adjustable wing controls to keep the unit close to the underwater substrate. The TOAD was damaged during the cruise
on 02/20/02, and subsequent tows were conducted as drift deployments. 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 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 is a camera sled based on the Guildline MiniBat model 8820 tow body. The frame was
configured with a single Sony DCR-PC110 Digital Video Camera in a modified Gates underwater housing, a Canon Power
Shot G1 Still Camera (modified by CRED engineers) in an Ikelite housing rated to 60 m slaved to an Ikelite DS-50
strobe, and two 500 W DeepSea Power & Light model 710-0400601 underwater lights. The Canon camera had a custom-built
timer that enabled the user to select a constant time interval (ranging from approximately 5 seconds to 2 minutes)
between photographs. An interval of 30 seconds was typically selected, which, assuming a mean velocity for the camera
sled of 1.5 knots, resulted in one photograph approximately every 20 m. Photograph resolution is 2048 x 1536 pixels
and file names are assigned sequentially and automatically by the camera, starting at 100-0000 after the camera's
memory is cleared. The MiniBAT pressure sensor and wing controller were also mounted on the frame but the pressure
sensor was not operational, after damage to the TOAD on 02/20/02. And the sled's wings were not installed thereafter.
The cable between the sled and the surface was an underwater load-bearing electrical cable. The TOAD computers were
located in the Electronics Lab of the Townsend Cromwell. The electronics box containing the power switches was
secured to the ship's fantail, and all other TOAD surface components were secured in the ship's wet lab.
Name & address of person collecting data:
Joyce Miller & Ron Hoeke
NOAA PIFSC
1125B Ala Moana Blvd
Honolulu, HI 98614
Data Files: Video data were recorded on two video tape recorders. Still photos were recorded on digital camera and
downloaded to the TOAD computer after the tow. 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, which increments by one for each new tow around that island. During TC0201 (NOAA Ship Townsend Cromwell's
first cruise in calendar year 2005) the consecutive numbers started at TUT02001. For following cruises, the tow numbers
will increment by 100, so the first tow on the next cruise will be tow number 100. Video tape labels, the navigation
(.glo and .shp) files, and paper log forms are annotated with the tow name and number, e.g., TUT02001. 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 `TUT02001a.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, `TUT02001a.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.
Resource Description: Digital video images that are geo-referenced to navigation files.
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ground condition
None planned
-170.92
-170.49
-14.20
-14.38
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
TC0201
CoRIS Discovery Thesaurus
Visual Images > Habitats
ISO 19115 Topic Category
environment
biota
CoRIS Place Thesaurus
OCEAN BASIN > Pacific Ocean > American Samoa > Tutuila Island (14S170W0016)
COUNTRY/TERRITORY > United States of America > American Samoa > American Samoa > Tutuila Island (14S170W0016)
OCEAN BASIN > Pacific Ocean > Tutuila Island > Pago Pago (14S170W0008)
COUNTRY/TERRITORY > United States of America > American Samoa > Tutuila Island > Pago Pago (14S170W0008)
OCEAN BASIN > Pacific Ocean > American Samoa > American Samoa (14S170W0000)
COUNTRY/TERRITORY > United States of America > American Samoa > American Samoa > American Samoa (14S170W0000)
CoRIS Region
AmSam
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
Pacific Islands Benthic Habitat Mapping Center, 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 on 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 and still photographs were reviewed by spot-checking to verify that
data were recorded. Navigation data were copied from the acquisition computer to the data archive. A metadata
extractor (gloMeta.py, version 9/28/04) 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 Avenue script named `toadimport.playback.ave', version 9/25/01, written by Ronald Hoeke.
20020529
Still photographs, nominally collected every 30 seconds and averaging approximately 20 m horizontal spacing between
them, were analyzed using a point count method. Five circles approximately 3 mm in diameter and spaced equidistantly
were drawn in a horizontal line on a piece of clear plastic sheet taped to a computer monitor screen. Within the
center of each circle the substrate (rock, sand, rubble, etc.) living cover (seagrass, scleractinian [stony] coral,
macroalgae, etc) and growth morphology of coral colonies (branching, encrusting, etc) were identified. Classification
information was recorded on a spreadsheet for each camera tow according to the codes described in the file
BenthicHabitatClassificationCodes_Metadata.xls. The substrate within the first circle is recorded under the column
labeled "S1" while the living cover and coral growth morphology within the same circle are recorded under the
columns labeled C1 and CM1. Data from the second circle are recorded under columns "S2," "C2," "CM2," and so on.
Spreadsheets are saved as a new file with data from each successive tow added to the bottom of the previous tow's
data, so that all camera sled data from Tutuila for cruise TC0201 is listed in chronological order in a single
worksheet. That is then saved as a database (.dbf) file and then imported into ArcGIS 9 as new shapefile, which
maintains the classification information entered every 30 seconds along a tow track.
20051017
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
Navigation information are recorded as successive lines in a comma-delimited ascii text
file, with a .glo extension. Each line of a GLO file includes the following data: the year, day of year, time,
latitude, longitude, water column depth, vehicle depth, layback, and wing angle. The field for vehicle depth does
not contain useful data. The field for wing angle is only valid for tows TUT1-TUT4. Each GLO file is imported
into MS Excel and saved as an Excel spreadsheet, and additional columns are added to the spreadsheet for each
navigation file to enable entry of classification information for each photograph.
List of navigation files:
tut02001a.glo
tut02002a.glo
tut02003a.glo
tut02004a.glo
tut02005a.glo
tut02006a.glo
CD-ROM
ISO 9660
MS Excel Spreadsheet
Navigation information are recorded as successive lines in a comma-delimited ascii text
file, with a .glo extension. Each line of a GLO file includes the following data: the year, day of year, time, latitude, longitude,
water column depth, vehicle depth, layback, and wing angle. The field for vehicle depth does not contain useful
data. The field for wing angle is only valid for tows TUT1-TUT4. Navigation information is recorded in ascii text
.GLO files which are imported into MS Excel and saved as an Excel spreadsheet. Additional columns are added to
the spreadsheet for each navigation file to enable entry of classification information for each photograph.
Spreadsheets with classification data entered are combined into a single spreadsheet with the data from each
stacked vertically in the order in which the data were collected. The name of that file is " TC0201_TUT-TOAD.xls"
and it is also exported as tab-delimited ascii text document with the same name, but with a .txt extension.
CD-ROM
ISO 9660
ArcGIS shapefile
Camera sled navigation data, converted to a single MS Excel spreadsheet with benthic
classification information from still photographs added, is exported as a database (.dbf) format file, and then
imported into ArcGIS and saved as a shape file. That file, TC0201_TUT-TOAD.shp and its associated Arc files with
the same name but different extensions (.dbf, .sbn, sbx, shp.xml, and .shx) contains an attribute table that
includes the classification data. Classifications for each still photograph from all camera sled tows conducted
around the island during this cruise follow the scheme described in the file "BenthicHabitatClassificationCodes_Metadata.xls."
CD-ROM
ISO 9660
mini digital video and VHS
These data were recorded on 2 video tapes, include 50 min of video data
covering 2.5 linear km of seabed. The second tape also includes data from
Palmyra Atoll.
List of video tapes:
TUT02001-003, VHS, Master
PAL02002-TUT02004-006, VHS, Master
TUT02001-003a, Mini DV, Master
TUT02003b, Mini Dv, Master
PAL02002-TUT02004a, Mini DV, Master
TUT02004b-006, Mini DV, Master
TUT02001-003a, Mini DV, Backup
TUT02003b, Mini Dv, Backup
PAL02002-TUT02004a, Mini DV, Backup
TUT02004b-006, Mini DV, Backup
Video cassette tape
Mini DV
JPG digital still photo
161 still images were taken that extend over 2.5 linear kilometers of seabed; poor photos were deleted
List of photo folders:
TUT02001: TUT_021002_0706 (30 photos)
TUT02002: TUT_021102_0611 (8 photos)
TUT02003: TUT_021102_0757 (54 photos)
TUT02004: TUT_022802_0635 (11 photos)
TUT02005: TUT_030302_0720 (15 photos)
TUT02005: TUT_030302_0731 (31 photos)
TUT02006: TUT_030302_0834 (12 photos)
CD-ROM
JPEG
None
20121214
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
20080502025532
None
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http://www.coris.noaa.gov/metadata/records/html/cred_toad_tutuila_tc0201_2002.html
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