The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. The total dose rate is due to natural sources of radiation and is computed by adding estimates of cosmic dose at ground level to the terrestrial dose. The terrestrial dose rate grid is derived as a linear combination of the filtered K, U and Th grids. A low pass filter is applied to this grid to generate the filtered total dose rate grid.
The Geological Survey of South Australia commissioned the Gawler Craton Airborne Survey (GCAS) as part of the PACE Copper initiative. The airborne geophysical survey was flown over parts of the Gawler Craton in South Australia. The program was designed to capture new baseline geoscientific data to provide further information on the geological context and setting of the area for mineral systems.
This Coober Pedy - dose rate no nasvd grid (AWAGS) has a cell size of 0.0004 degrees (approximately 42m) and shows the total dose rate of the Coober Pedy West Airborne Magnetic Radiometric and DEM Survey, SA, 2017 survey. The data used to produce this grid was acquired in 2017 by the SA Government, and consisted of 90697 line-kilometres of data at 200m line spacing and 60m terrain clearance.
