CRED Optical Validation Data at the islands of Ofu and Olosega in American Samoa, 2002 to Support Benthic Habitat Mapping (TOAD)

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator:
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)
Publication_Date: 200509
Title:
CRED Optical Validation Data at the islands of Ofu and Olosega in American Samoa, 2002 to Support Benthic Habitat Mapping (TOAD)
Geospatial_Data_Presentation_Form:
Video and photo imagery, track line navigation files, and log sheets
Online_Linkage: <http://www.soest.hawaii.edu/pibhmc/>
Online_Linkage:
<http://www.soest.hawaii.edu/pibhmc/pibhmc_amsamoa_ofu_optical.htm>
Description:
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 at Ofu and Olosega, American Samoa to support Benthic Habitat Mapping efforts during NOAA Ship Townsend Cromwell cruise TC0201.
Purpose:
These data provide optical observations that will be correlated with bathymetry and acoustic backscatter imagery to develop a benthic habitat map of Ofu and Olosega. Refer to supplemental information for description of instrument and survey.
Supplemental_Information:
Ofu and Olosega Islands are part of the Manu'a Island group in American Samoa, situated approximately 100 km northeast of Tutuila and 20km west of Ta'u. Centered at 14.17 degrees S, 169.65 degrees W, the twin islands have very little human settlement. Ofu and Olosega are steep, volcanic high islands that lie only 75 m apart and are connected by a bridge and road built across the shallow reef flat. Shallow multibeam mapping was conducted in 2004 and revealed approximately 60 km2 of previously uncharted bank top (greater than 300 m) that extends 0.2 to 2 km from shore and then drops abruptly to oceanic depths. An underwater portion of the National Park of American Samoa, which has exceptionally prolific coral growth, is located on the south shore of Ofu Island.

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 that 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 and 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 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 IRC NMFS/PIFSC/CRED 1845 WASP Blvd., Building 176 Honolulu, HI 96818

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 three-letter designator for the island area, followed by a two-digit year and a three-digit tow number, which increments by one for each new tow around that island. During TC0201 (NOAA Ship Townsend Cromwell's 1st cruise in calendar year 2002) the consecutive tows at Ofu started at OFU02001. For following cruises, the tow numbers will increment by 100, so the first tow on the next cruise to Ofu in 2002 will be tow number OFU02100. Video tape labels, the navigation files (*.glo) and paper log forms are annotated with the tow name and number, e.g., OFU02001. If the navigation file is edited during processing the file name has a suffix 'a' added. For example, for a navigation data file named OFU02001a.glo, the 'a' would indicate that 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, 'OFU02001a.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.

Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20020214
Ending_Date: 20020215
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -169.705274
East_Bounding_Coordinate: -169.583687
North_Bounding_Coordinate: -14.133505
South_Bounding_Coordinate: -14.203385
Keywords:
Theme:
Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus
Theme_Keyword: EARTH SCIENCE > Biosphere > Aquatic Habitat > Benthic Habitat
Theme_Keyword:
EARTH SCIENCE > Biosphere > Zoology > Corals > Reef monitoring and assessment > Photographic analysis > Videography
Theme_Keyword:
EARTH SCIENCE > Biosphere > Zoology > Corals > Reef monitoring and assessment > Mapping
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Tethered Optical Assessment Device (TOAD)
Theme_Keyword: Underwater video
Theme_Keyword: TC0201
Theme:
Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus
Theme_Keyword: Visual Images > Habitats
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: environment
Theme_Keyword: 007
Theme_Keyword: biota
Theme_Keyword: 002
Place:
Place_Keyword_Thesaurus: CoRIS Place Thesaurus
Place_Keyword:
OCEAN BASIN > Pacific Ocean > Manu'a Group > Ofu Island (14S169W0013)
Place_Keyword:
COUNTRY/TERRITORY > United States of America > American Samoa > American Samoa > Ofu Island (14S169W0013)
Place_Keyword:
OCEAN BASIN > Pacific Ocean > Manu'a Group > Olosega Island (14S169W0014)
Place_Keyword:
COUNTRY/TERRITORY > United States of America > American Samoa > American Samoa > Olosega Island (14S169W0014)
Place:
Place_Keyword_Thesaurus: CoRIS Region
Place_Keyword: AmSam
Access_Constraints: None
Use_Constraints:
Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as the source of this information.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
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)
Contact_Person: John Rooney
Contact_Address:
Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818
Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Data_Set_Credit:
Pacific Islands Benthic Habitat Mapping Center, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA
Security_Information:
Security_Classification_System: Not applicable
Security_Classification: Unclassified
Security_Handling_Description: Not applicable

Data_Quality_Information:
Logical_Consistency_Report: Unspecified
Completeness_Report: Complete
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
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.
Lineage:
Process_Step:
Process_Description:
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 3/17/06) was run to summarize the navigation data and test for errors. If errors were detected in a record, a copy of the data file was made (the 'a.glo' file mentioned above), that record was automatically flagged as invalid, and corrections were made if possible. 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 imported to ArcGIS 9.x.

Still photographs, collected every 30 seconds and averaging approximately 20m horizontal spacing between them, were analyzed using a point count method. 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 (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.

Process_Date: 20051117

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
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)
Contact_Person: John Rooney
Contact_Address:
Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818
Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Resource_Description: Offline Data
Distribution_Liability:
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ASCII
Format_Information_Content:
Each comma-delimited record contains 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 TUT02001-004.

List of navigation files: The following are shape files compatible with ESRI GIS software. Each item in the list a set of files used by ArcView/ArcGIS to display and access the associated data. Each item in the list has associated .shp, .dbf, and .shx files. They may additionally have .prj, .sbn, and .sbx files if the project's projection requires it. List of Navigation files: ofu02001a.glo ofu02002b.glo ofu02003a.glo

Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Format: ISO 9660
Digital_Form:
Digital_Transfer_Information:
Format_Name: mini digital video and VHS
Format_Information_Content:
These data were recorded on 2 video tapes, include 50 min of video data covering 2.5 linear km of seabed. List of video tapes: OFU02001-003, VHS, Master OFU02001-003, Mini DV, Master OFU02001-003, Mini Dv, Backup
Digital_Transfer_Option:
Offline_Option:
Offline_Media: Video cassette
Recording_Format: mini dv
Digital_Form:
Digital_Transfer_Information:
Format_Name: JPG digital still photo
Format_Information_Content:
161 still images were taken that extend over 2.5 linear kilometers of seabed; poor photos were deleted List of photo folders: OFU02001: OFU_021402_0540 (78 photos) OFU02002: OFU_021402_0738 (32 photos) OFU02003: None
Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Format: JPEG
Digital_Form:
Digital_Transfer_Information:
Format_Name: text file
Format_Information_Content:
The time, location and other information from each photograph, as well as classifications of the benthic substrate and living cover and comments on specific photograph are recorded in tabular form for each camera sled tow in the file OpticClass_TC0201_OFU.xls.
Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Format: ASCII
Fees: None

Metadata_Reference_Information:
Metadata_Date: 20140312
Metadata_Review_Date: 20100504
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
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)
Contact_Address:
Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818
Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

CoRIS:
CoRIS_ID: 20100504024906
CoRIS_Children: None
CoRIS_Beginning_Date: 20020214
CoRIS_Ending_Date: 20020215
CoRIS_Metadata_Link:
<http://www.coris.noaa.gov/metadata/records/html/cred_toad_ofu_olosega_tc0201_2002.html>
CoRIS_Tracking_ID: 1687

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