Abstract:
Bathymetric surveys of Brown Bay, O'Brien Bay and Newcomb Bay in the Windmill Islands.
This dataset resulted from bathymetric surveys of Brown Bay, O'Brien Bay and Newcomb Bay in the Windmill Islands, carried out in February and March 1997 as part of ASAC Project 2201. The surveys were carried out by Jonny Stark and Tim Ryan in the workboat the 'Southern Comfort'.
Description:
Access to data files via a registered zip file containing 3 folders and a readme file explaining what is in the folders: 1.Brown Bay 2.Newcomb Bay 3.O'Brien Bay
Quality
An EK500 Echosounder was used to determine depth with the sensor mounted on a boom and positioned approximately a metre below the water surface to avoid disturbance from the wake of the boat. The data were corrected to allow for the sensor not being at the surface. Real time GPS horizontal corrections were sent to the boat from an onshore GPS base station. The depth data and GPS data were received ... by an integrated logging system on the boat which included a SUN computer. The logging system provided differentially corrected GPS locations to a Garmin handheld receiver. Occasionally there were dropouts in the base station data due to factors such as weather and proximity to cliffs. The horizontal coordinates are in a UTM zone 49 projection. Data Files in geographical coordinates have also been provided.
THE DATA ARE NOT FOR NAVIGATION PURPOSES
The zip file available for download includes the original data in text files. The data were manipulated for the creation of digital elevation models of the 3 bays. These DEMs are available for download and the metadata records (obrien_bay_dem, brown_bay_dem and newcomb_bay_dem) describe the processing of the data.
Usually mapped to a Universal Transverse Mercator projection, Zone 49S, Datum WGS-84.
Access Constraints
These data are available for download from the URL given below.