This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied.
Digital Terrain Model derived from radar elevations from NASA's SRTM (Shuttle Radar Topography Mission) project in Feb 2000. Raster resolution is 1 arc seconds of latitude/longitude which is equivalent to approximately 30 metres. It consists of a regular grid representing ground surface topography, and where possible, excluding other features such as vegetation and man-made structures.
The SRTM data was collected during a 10 day NASA Space Shuttle mission in February 2000 (Kobrick, 2006). It was processed to produce a 1 arc second digital surface model covering most of the earth's landmass and publicly released as a 3 second resolution product. The 1 second version was provided to CSIRO by Australia's Defence Imagery and Geospatial Organisation (DIGO) with permission to release cleaned up products to government users only. The data was acquired by interferometric synthetic aperture radar, meaning that the information is contained in the interference patterns between the radar signals collected by two antennas, one of which was inside the Shuttle and the other was on a 60m boom. The Shuttle was oriented to point the antennas at 45 degrees to the ground to optimise the effect of topography on the interference patterns, but this also has the effect of obscuring any steep areas facing away from the Shuttle. This is mostly overcome by collecting overlapping swathes from different orbits, although some canyons and steep areas have no data. Other areas that did not produce a good radar return signal also have no data.Comparison of SRTM with reference data (Rodriguez et al, 2006) showed that 90% of tested heights were within 6m of the reference heights. In much of the clear flat areas of Australia the height errors are less than 3m, although there are some areas where the errors are much larger. Trees and buildings produce offsets in the elevation much larger than these height errors, since the radar frequency used by SRTM does not penetrate them.
SA Department of Environment, Water and Natural Resources (2015) ARC elevation - PED. Bioregional Assessment Source Dataset. Viewed 12 October 2016, http://data.bioregionalassessments.gov.au/dataset/ac790bcf-7809-4ba1-b3ce-0faa8637c5e1.