Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled
equipped with an underwater digital video camera and lights, in the Saipan Anchorage area. Data were collected using
TOAD during two and a half weeks of small boat-based TOAD deployments.
A report detailing results of the study was generated to assist the Military Sealift Command in their
efforts to increase the number of pre-position vessels stationed there.
These data provides optical observations that have been used to provide information on the distribution of coral communities
in Garapan anchorage out side of Saipan Harbor, CNMI.
Saipan, the largest of the Northern Mariana Islands, has a land area of 122 km2 and is approximately 20 km long and
9 km wide. The island consists of a volcanic core enveloped by younger coral reef-derived limestone formations. The
island has the most diverse types of coral reefs and associated habitats in the Commonwealth. A fringing and barrier
reef system protects the majority of the beaches along the western and coastal plains. The western side of the island
is the most populated and the coral reefs along these areas are negatively affected by human activity. Continuing
sediment and nutrient pollution combined with sporadic stressors such as outbreaks of crown-of-thorns starfish (COTS)
(Acanthaster planci) and temperature-induced bleaching affect many of Saipan's western and southeastern reefs.
Furthermore, coral habitat on two large offshore banks (18 km x 22 km) in water depths between 30 m and 60 m on the
western side of Saipan are negatively affected by the anchorage of commercial and naval vessels. It is these two banks
that were the subject of the study reported here.
Optical validation data were collected the Tethered Optical Assessment Device (TOAD), a sled equipped with underwater video camera and lights.
These data are used to provide optical information regarding benthic and fish communities. They have also been used to
provide ground-truth validation for benthic habitat maps based on multibeam echosounder surveys, but these are presented in a
separate product, available on the PIBHMC website.
From December 3-16 2004, CRED personnel and contractors conducted towed video surveys in the Saipan Anchorage, CNMI
aboard the 62-ft-long Carolinian, one of the vessels owned and operated by Saipan Crewboats, Inc., and regularly
chartered by the U.S. Navy. Operations were conducted during daylight hours, with video data collected using a new
underwater camera sled, designed and fabricated by Deep Ocean Engineering, Inc. (DOE). The camera sled was attached
via umbilical cable to a control console located on board the Carolinian. The camera sled was deployed from the port
or starboard side of the Carolinian depending on the prevailing current and wind conditions. A video display monitor
mounted on the control console was used to monitor the position of the sled relative to the seafloor. Instructions to
raise/lower the sled were relayed to CRED personnel on deck to maintain close proximity of the sled to the seafloor
and to avoid collisions with seafloor highs.
Equipment Description: The TOAD sled body is constructed from a shortened Phantom ROV body with a tail
piece added for stability. It is equipped with a Deep Sea Power & Light Multi SeaCam 2060 color video camera, two 500
W DeepSea Power & Light Multi-SeaLite model 1050 underwater lights, a sonar altimeter to detect the height of the
camera above the seafloor, a pair of parallel lasers to determine the size/scale of viewed objects, a compass to determine
the sled heading and orientation, and a depth (pressure) sensor. The video signal from the sled is send via a coaxial
conductor within a 200 m long and 127 mm diameter umbilical cable to a topside control unit. The video data are
recorded to digital video cassette using a video recorder mounted in the control console. Hypack Max (version 2.12A)
hydrographic survey software was used to record GPS data, water depth, length of umbilical cable in the water, and
camera sled information (height, heading, etc.), which provide ship and camera sled positions for the duration of
Data Files: Video data were recorded on video tape recorders and the position of the camera sled was recorded using
a GPS signal and different software packages, as described above.
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. During SB0401 the consecutive numbers started
at SAI04001. Video tape labels and paper log forms are annotated with the tow name.
Data recorded using Hypack software follow the Hypack CHS filename
format consisting of the year, the first two letters of the platform name, the Julian date, and the hour and minute
in which the file was started, and the extension "raw." For example, a file collected on Dec. 10, 2004 (Julian date
345) aboard the Carolinian starting at time 1935 would be 2004CA3451935.raw.
Time Correlation: All times are based on UTC. Clocks were manually synchronized prior to starting data collection
each day of operations.
Resource Description: Digital video imagery that is geo-referenced to navigation files.
Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as the source of
this information. Use of the report is limited to U.S. Navy personnel or contractors with a need to know about this
project. There are no use constraints on the data upon which the report is based.
1845 WASP Blvd., Building 176
Benthic Habitat Mapping Group, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA
The Hypack software used in the 2004 data collection includes a window for manual entry of the length of camera sled cable paid out, a utility to enter horizontal and vertical offsets between the GPS antenna and sheave over which the camera sled cable passes, and a built-in caternary function. Using these additional data, the Hypack software automatically adjusts the postion of the GPS antenna to generate and record an estimate of camera sled position. Analysis of tow data indicate that horizontal positional uncertainty associated with the location of the camera sled recorded in Hypack is plus or minus 13 m.
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. Raw data files recorded slightly different data depending on the software used, but both record the time, horizontal position, and ship's heading information, and were copied from the acquisition computer to the data archive. Tow-specific metadata were recorded in the data archive in the same location as the raw data, in a spreadsheet that was then referred to in creating metadata records of each island where data were collected during the cruise. Raw data files were exported as comma-delimited text files which were then imported into ArcGIS v8.3 and saved as shapefiles. Specific frames spaced every 20 m from the video were analyzed. For each, five circles approximately 0.5 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, living cover, and growth morphology of coral colonies were identified. Classification information was recorded on a spreadsheet for each camera tow according to the codes and include the type of substrate, living cover (if any), and dominant variation in relief seen in the image. Spreadsheets with benthic classification data from video analysis are attributed to the appropriate tow track shapefile and along-track location. Color coding is then applied to highlight features of interest, such as the percentage of the seafloor covered by living corals or other benthic fauna found at each location or different types of substrate.
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.
All navigation files contain information on the UTC date and time, horizontal position of the sled, and heading of the ship over the period of time that the camera sled is in the water. A total of 66 navigation files were collected, starting chronologically with 2004CA3380459.RAW and ending with 2004CA3510158.RAW
Video data are available covering in excess of 120 km of seabed. These data were recorded on 73 video tapes. List of video tapes: SAI04001, Mini DV, Master and Backup SAI04003, Mini DV, Master and Backup SAI04004, Mini DV, Master and Backup SAI04005, MiniDV, Master and Backup SAI04006a, MiniDV, Master and Backup SAI04006b-007a, MiniDV, Master and Backup SAI04007b, MiniDV, Master and Backup SAI04008, MiniDV, Master and Backup SAI04009, MiniDV, Master and Backup SAI04010a, MiniDV, Master and Backup SAI04010b, MiniDV, Master and Backup SAI04010c, MiniDV, Master and Backup SAI04011a, MiniDV, Master and Backup SAI04011b, MiniDV, Master and Backup SAI04011c, MiniDV, Master and Backup SAI04011d, MiniDV, Master and Backup SAI04012a, MiniDV, Master and Backup SAI04012b, MiniDV, Master and Backup SAI04013a, MiniDV, Master and Backup SAI04013b, MiniDV, Master and Backup SAI04014, MiniDV, Master and Backup SAI04015a, MiniDV, Master and Backup SAI04015b, MiniDV, Master and Backup SAI04016a, MiniDV, Master and Backup SAI04016b, MiniDV, Master and Backup SAI04017, MiniDV, Master and Backup SAI04018a, MiniDV, Master and Backup SAI04018b, MiniDV, Master and Backup SAI04019, MiniDV, Master and Backup SAI04020a, MiniDV, Master and Backup SAI04020b, MiniDV, Master and Backup SAI04021a, MiniDV, Master and Backup SAI04021b, MiniDV, Master and Backup SAI04022a, MiniDV, Master and Backup SAI04022b, MiniDV, Master and Backup SAI04023, MiniDV, Master and Backup SAI04024, MiniDV, Master and Backup SAI04025, MiniDV, Master and Backup SAI04026, MiniDV, Master and Backup SAI04027a, MiniDV, Master and Backup SAI04027b, MiniDV, Master and Backup SAI04028a, MiniDV, Master and Backup SAI04028b, MiniDV, Master and Backup SAI04030, MiniDV, Master and Backup SAI04031a, MiniDV, Master and Backup SAI04031b, MiniDV, Master and Backup SAI04032, MiniDV, Master and Backup SAI04033, MiniDV, Master and Backup SAI04034, MiniDV, Master and Backup SAI04035a, MiniDV, Master and Backup SAI04035b, MiniDV, Master and Backup SAI04035c, MiniDV, Master and Backup SAI04035d, MiniDV, Master and Backup SAI04036, MiniDV, Master and Backup SAI04037, MiniDV, Master and Backup SAI04038a, MiniDV, Master and Backup SAI04038b, MiniDV, Master and Backup SAI04039a, MiniDV, Master and Backup SAI04039b, MiniDV, Master and Backup SAI04039c, MiniDV, Master and Backup SAI04040a, MiniDV, Master and Backup SAI04040b, MiniDV, Master and Backup SAI04041, MiniDV, Master and Backup SAI04042, MiniDV, Master and Backup SAI04043a, MiniDV, Master and Backup SAI04043b, MiniDV, Master and Backup SAI04043c, MiniDV, Master and Backup SAI04044, MiniDV, Master and Backup