CRED Optical Validation Data at the island of Tutuila in American Samoa, 2008 to Support Benthic Habitat Mapping

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Frequently anticipated questions:


What does this data set describe?

Title:
CRED Optical Validation Data at the island of Tutuila in American Samoa, 2008 to Support Benthic Habitat Mapping
Abstract:
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 using TOAD during the NOAA Ship Hi'ialakai cruise HI0802, in a separate expedition involving about two and a half weeks of small boat-based (Bonavista II) TOAD deployments. Data were collected within the US Territory of American Samoa, around the island of Tutuila to support Benthic Habitat Mapping efforts.
Supplemental_Information:
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 14.30N, 169.75W, 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 ~5 sq. km of coastline. 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 for benthic habitat maps based on multibeam echosounder surveys. Camera sled deployments were conducted during daylight hours, usually between 0600 and 1700. The duration of each tow varied but averaged about 40 minutes of bottom time at a given location. The camera sled was deployed from the starboard gunwhale of the Bonavista II. At each station 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 the video tape recorder. When the camera reached bottom the deck crew was notified by radio to stop lowering. The vessel then began a course of a predetermined heading maintaining a speed of approximately 1 knot for the remainder of the survey. 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 starboard gunwhale of the vessel. The TOAD sled body used for the 2008 data collection is constructed from a shortened Phantom ROV body with a tail piece added for stability. It is equipped with a Deep Sea Power and Light Multi SeaCam 2060 color video camera, two 500 W DeepSea Power and 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. All TOAD surface components were located below deck in the V berth of the vessel within an equipment rack secured to the benches.

Data Files: Video data were recorded on a video tape recorder. The position of the camera sled was recorded using Hypack Max version 6.2b survey software.

File naming convention: Each tow is given a name consisting of a 3-letter designator for the island area followed by two-digit year and three-digit tow number. For example, during BV0801 (Bonavista II's 1st cruise in calendar year 2008) the first tow was called TUT08001. Video tape labels and paper log forms are annotated with the tow name. Data files recorded in Hypack software followed their 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. For example, a file collected on July 18, 2005 (Julian date 199) aboard the Hi'ialakai starting at time 1935 would be 2005HI1991935.

Time Correlation: All times are based on UTC. Three clocks were manually synchronized prior to starting data collection; the clock in the video character generator that was used to annotate the video tape, in the video cassette recorder, and in the computer running the Hypack Max software. These clocks were set to UTC at the beginning of each day's operations.

Name & address of person collecting data: John Rooney NOAA IRC NMFS/PIFSC/CRED 1845 WASP Blvd., Building 176 Honolulu, HI 96818

Resource Description: Digital video imagery that is geo-referenced to navigation files.

  1. How should this data set be cited?

    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), 200805, CRED Optical Validation Data at the island of Tutuila in American Samoa, 2008 to Support Benthic Habitat Mapping.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -170.92403
    East_Bounding_Coordinate: -170.49467
    North_Bounding_Coordinate: -14.21815
    South_Bounding_Coordinate: -14.33216

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 15-Feb-2008
    Ending_Date: 25-Feb-2008
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: Video imagery, track line navigation files, and log sheets

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

    2. What coordinate system is used to represent geographic features?

  7. How does the data set describe geographic features?


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    Pacific Island Benthic Habitat Mapping Center, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA

  3. To whom should users address questions about the data?

    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)
    Attn: John Rooney
    NOAA IRC
    Honolulu, HI 96818

    808 725-5360 (voice)
    808 725-5429 (FAX)
    nmfs.pic.credinfo@noaa.gov

    Contact_Instructions: e-mail preferred


Why was the data set created?

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.


How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: 04-Apr-2008 (process 1 of 1)
    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 using Hypack Max software include time, horizontal position, and vessel's heading information 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 v9.2 and saved as shapefiles.

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

    Hypack Max 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 data, Hypack Max automatically estimates the camera sled's 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.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    Complete

  5. How consistent are the relationships among the observations, including topology?

    Unspecified


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:
Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as the source of this information.

  1. Who distributes the data set? (Distributor 1 of 1)

    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)
    Attn: John Rooney
    NOAA IRC
    Honolulu, HI 96818

    808 725-5360 (voice)
    808 725-5429 (FAX)
    nmfs.pic.credinfo@noaa.gov

    Contact_Instructions: e-mail preferred
  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    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.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 23-Apr-2014
Last Reviewed: 02-Dec-2008
Metadata author:
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)
Attn: CRED Data Management Team
NOAA IRC
Honolulu, HI 96818

808 725-5360 (voice)
808 725-5429 (FAX)
nmfs.pic.credinfo@noaa.gov

Contact_Instructions: e-mail preferred
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.9.13 on Fri Aug 22 10:41:47 2014