The 3D inversion of airborne gamma-ray spectrometric data
Brian Minty 1 3 Ross Brodie 2
+ Author Affiliations
- Author Affiliations
1 Minty Geophysics, PO Box 3229, Weston, ACT 2611, Australia.
2 Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia.
3 Corresponding author. Email: Brian.Minty@mintygeophysics.com
Exploration Geophysics 47(2) 150-157 https://doi.org/10.1071/EG14110
Submitted: 8 November 2014 Accepted: 26 June 2015 Published: 28 July 2015
Abstract
We present a new method for the inversion of airborne gamma-ray spectrometric line data to a regular grid of radioelement concentration estimates on the ground. The method incorporates the height of the aircraft, the 3D terrain within the field of view of the spectrometer, the directional sensitivity of rectangular detectors, and a source model comprising vertical rectangular prisms with the same horizontal dimensions as the required grid cell size. The top of each prism is a plane surface derived from a best-fit plane to the digital elevation model of the earth’s surface within each grid cell area.
The method is a significant improvement on current methods, and gives superior interpolation between flight lines. It also eliminates terrain effects that would normally remain in the data after the conventional processing of these data assuming a flat-earth model.
Key words: deconvolution, gamma-ray spectrometry, inversion, terrain correction, topographic correction.
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