CRED Optical Validation Data for Saipan Anchorage Commonwealth of the Northern Mariana Islands, 2004

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Frequently anticipated questions:


What does this data set describe?

Title:
CRED Optical Validation Data for Saipan Anchorage Commonwealth of the Northern Mariana Islands, 2004
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, 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.
Supplemental_Information:
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 individual tows.

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.

  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), 200505, CRED Optical Validation Data for Saipan Anchorage Commonwealth of the Northern Mariana Islands, 2004.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: 145.61
    East_Bounding_Coordinate: 145.70
    North_Bounding_Coordinate: 15.23
    South_Bounding_Coordinate: 15.13

  3. What does it look like?

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

    Beginning_Date: 03-Dec-2004
    Ending_Date: 16-Dec-2004
    Currentness_Reference: ground condition

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

    Geospatial_Data_Presentation_Form:
    raster 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?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Decimal Degrees.

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257223563.

  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?

    Benthic Habitat Mapping Group, 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)
    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 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.


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: 30-May-2005 (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 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.

  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?

    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.

  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:
Distribution of the report is limited to NOAA and U.S. Navy personnel or contractors with a need to know about this project. There are no access constraints on the data upon which the report is based.
Use_Constraints:
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.

  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)
    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?

    Offline 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: 12-Mar-2014
Last Reviewed: 12-Sep-2011
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)
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 Thu Dec 18 10:43:46 2014