The Kauring Airborne Gravity Test Site, Western Australia
Abstract
A test site for airborne gravity (AG) systems has been established at Kauring, approximately 100 km east of Perth, Western Australia. The site was chosen using a range of criteria that included being within 200 km of Jandakot Airport in Perth where most of the airborne systems would be based at one time or another when operating in Australia, being free of low level flight restrictions, having minimal human infrastructure in the central 20 by 20 km area, and the presence of gentle to rolling terrain rather than deeply incised topography or an extensive flat plain with very low relief. In anticipation of catering for airborne gravity gradiometer (AGG) systems, the site was required to have a gravity gradient feature with clear response in the wavelength range of 100 m to 2 km in a 5 by 5 km core region. The existence of closely-spaced, high quality ground gravity data would have been a positive factor for selecting a test site, but a search of the national gravity database indicated that there were no such data sets in the search area. Consequently, a ground vertical gravity acquisition program for the chosen site at Kauring was arranged by the Geological Survey of Western Australia (GSWA), Geoscience Australia (GA), and Rio Tinto Exploration. To support AG system tests, a 150 by 150 km area was covered with a maximum station spacing of 2 by 2 km, and the central area of 20 by 20 km was covered with a maximum station spacing of 0.5 by 0.5 km. These data are freely available from GSWA and GA. To support AGG system tests, the core 5 by 5 km area would need to have stations with much closer spacing (e.g., 100 by 100 m). A variety of publicly available digital terrain data sets are available (e.g., SRTM 3-second data (~90 m), ASTER GDEM 1-second data (~30 m), GEODATA 9-second data (~300 m), etc.). Acquisition of a LIDAR-based high-resolution digital terrain model (DTM) for the central 20 by 20 km area is being considered. A DTM of this nature for the core 5 by 5 km area would be essential to support AGG system tests. The test site will allow us to compare AG data to the ground gravity data (or products derived from these data). It will also allow us to compare different AG systems using a common set of criteria when they are operated under the same conditions. As airborne data sets are acquired and made available for public distribution from GA, we will have an increasingly valuable resource for developing and demonstrating data processing, modelling and interpretation methods. Projects to study different methods for production of terrain corrections, to upward continue the ground data, and to transform the vertical gravity data into horizontal gravity components or gravity gradient tensor components have already commenced. In addition to catering for AGG systems, the site may also be used in the future to demonstrate and compare various airborne magnetic systems (TMI, vector, and gradient tensor systems) and digital terrain mapping systems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.G51A0656L
- Keywords:
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- 1219 GEODESY AND GRAVITY / Gravity anomalies and Earth structure;
- 1244 GEODESY AND GRAVITY / Standards and absolute measurements;
- 1294 GEODESY AND GRAVITY / Instruments and techniques