406af3af-e466-434c-84fa-63d6c02af35e urn:uuid eng UTF-8 dataset Dataset 2022-05-10T00:56:24 creation ISO 19115 2016 point 7279 NSW Marine Estate Towed Video Imagery 406af3af-e466-434c-84fa-63d6c02af35e Raw downward facing still imagery of the seabed over the NSW continental shelf acquired using NSW government's (Department of Climate Change, Energy, the Environment and Water) towed video system aboard RV Bombora. Acquisition is ongoing (>2015) predominantly funded by the department under Coastal Reform Climate Change Fund project 'State-wide Science' and/or by various collaborative agencies (DPI; Parks Australia; FRDC) and educational institutions (UoW: UTas). Imagery is captured over areas to 1) ground-truth seabed typologies and validate habitat boundaries derived from multi-beam echosounder (MBES) surveys (www.aodn.org.au or www.ausseabed.gov.au) and/or 2) habitat assessments and monitoring to capture broad distribution of seabed benthic communities. For biodiversity-type assessments, imagery is captured, and transects/sites are selected in a sampling design in accordance with the Australian Field Manuals for Marine Sampling. Imagery captured is generally of benthic habitats in 10-120m of water depth over the NSW inner shelf. Georeferenced (XYZ) and time-stamped (UTC) still imagery is accessible via SEED, the online annotation platform Squidle+ and SeaMap Australia. MARINE-Biology MARINE-Coasts MARINE-Reefs Marine conservation PHOTOGRAPHY-AND-IMAGERY-Remote-Sensing baseline monitoring dataset 2020-05-18T00:00:00 As the imagery is acquired using a moving platform some images may capture the same section of seabed. Survey speed of ~1kt (0.51m/s); image capture rate 1 image every 2 seconds; and approximate area of seabed captured in each image. nb: tow-fish roll, pitch and heave values are recorded by the video camera and saved within the video data file. dataset 2020-05-18T00:00:00 Squidle+ ingestion of data requires a position and an altimetry value or height of the 'tow fish' above the seabed. At the time of acquisition, the the towed video system did not have an altimeter and thus the height of the tow fish was estimated as Tow-Fish Altitude = [Water Depth at Tow-Fish (from MBES survey)] - [Tow-Fish Pressure Sensor Depth] + [P-Sensor to SLR camera (offset =0.52)] nb. P-sensor value is not corrected for tide whereas MBES data is static to AHD. XY position of fish is determined by relative position of USBL transponder (fish) to transceiver (vessel). GPS position is G2 quality (~0.4-0.5 in real-time) and is relative to the vessels Centre of Mass (reference frame 0:0:0) with a 12.4m forward offset (X = -1.5) from transceiver to COM entered in the USBL software (Y = 0). USBL heading offset is checked following each installation (nominally 23 degrees from centreline) and USBL (Tracklink, USA) precision is 3 degrees of slant range value. Original image time-stamping is synched with computer UTC (<1s) but naming convention uses USBL/Video text feed based on POS MV output.