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: 200606 Title: CRED Optical Validation Data at Laysan Island, 2002 to Support Benthic Habitat Mapping Geospatial_Data_Presentation_Form: Video and photo imagery, track line navigation files, and log sheets Online_Linkage: http://www.soest.hawaii.edu/pibhmc/ 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 the Northwestern Hawaiian Islands, Laysan Island to support Benthic Habitat Mapping efforts. Purpose: This data provides optical observations that will be correlated with bathymetry and acoustic backscatter imagery to develop a benthic habitat map of Laysan Island. Refer to supplemental information for description of instrument and survey. Supplemental_Information: Laysan Island, located at 25.75N, 171.75W, is an isolated coral island. The underlying basaltic structure is estimated to be 17 million years old. The island is the largest in the Northwestern Hawaiian Island with 4.11 sq. km of land area and an interior hypersaline lake. Its coral reef habitat is relatively small, including 57 sq. km of banks less than 100 m. 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 & 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 02/20/02and 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 & Ronald 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 3-letter designator for the island area, "LAY" in this case followed by a five-digit tow number. The first two digits indicate the last two digits of the calendar year, i.e., "02" is used for this cruise, which took place in 2002. The last three numbers indicate the consecutive number of the tow for that island and year, and start on the next hundred for subsequent cruises in that year to the same island. During TC0207 the consecutive numbers started at 020. Video tape labels, the navigation files (*.glo) and paper log forms are all annotated with the tow name. 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, "LAY02002.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: Single_Date/Time: Calendar_Date: 20020916 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -171.77085 East_Bounding_Coordinate: -171.7362 North_Bounding_Coordinate: 25.73207 South_Bounding_Coordinate: 25.71863 Keywords: Theme: Theme_Keyword_Thesaurus: NCEI Geoportal Filter Theme_Keyword: CoRIS_Metadata Theme: Theme_Keyword_Thesaurus: CRCP Project Theme_Keyword: Benthic Habitat Mapping and Characterization - Northwestern and Main Hawaiian Islands Theme_Keyword: 1217 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 > Mapping Theme_Keyword: EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Photographic Analysis > Videography Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Tethered Optical Assessment Device (TOAD) Theme_Keyword: Underwater video Theme_Keyword: TC0207 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 > Central Pacific Ocean > Northwestern Hawaiian Islands > Laysan Island (25N171W0001) Place_Keyword: COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Laysan Island (25N171W0001) Place_Keyword: OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands (28N178W0000) Place_Keyword: COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Northwestern Hawaiian Islands (28N178W0000) Place: Place_Keyword_Thesaurus: CoRIS Region Place_Keyword: NWHI 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_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: Benthic Habitat Mapping Group, 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 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 3/06) 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 ArcView Avenue script named "TOAD.Import.Playback", version 9/25/01, written by Ronald Hoeke. Process_Date: 20041015 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0001 Longitude_Resolution: 0.0001 Geographic_Coordinate_Units: Decimal Degrees Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257224 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: No correction Depth_Resolution: 0.1 Depth_Distance_Units: meters Depth_Encoding_Method: Attribute Values 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_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, velocity north and east, water column depth, vehicle depth, layback, and wing angle. For this data set the fields for vehicle depth and wing angle do not contain useful data. List of navigation files: LAY02002.glo Digital_Transfer_Option: Offline_Option: Offline_Media: CD-ROM Recording_Format: ISO 9660 Digital_Form: Digital_Transfer_Information: Format_Name: mini digital video Format_Information_Content: List of video tapes: LAY02002, VHS, Master LAY02002, Mini Dv, Master LAY02002, Mini Dv, Backup Digital_Transfer_Option: Offline_Option: Offline_Media: Video cassette tape Recording_Format: Mini DV Digital_Form: Digital_Transfer_Information: Format_Name: JPG digital still photo Format_Information_Content: 114 still images available; poor photos were enhanced or deleted List of photo folders: LAY02002: LAY_091602_0630 (114 photos) Digital_Transfer_Option: Offline_Option: Offline_Media: CD-ROM Recording_Format: JPEG Fees: None Metadata_Reference_Information: Metadata_Date: 20200329 Metadata_Review_Date: 20110323 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 Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 CoRIS: CoRIS_ID: 20080502025802 CoRIS_Children: None CoRIS_Beginning_Date: 20020916 CoRIS_Ending_Date: 20020916 CoRIS_Metadata_Link: https://www.coris.noaa.gov/metadata/records/html/cred_toad_laysan_tc0207_2002.html CoRIS_Tracking_ID: 1480