Improving the quality of aerial gamma-ray surveys

Abstract

A review of the parameters used in processing aerial gamma-ray survey data from a number of recent surveys showed that many surveys were processed with incorrect values. Many of the problems arise from unrecognized variations in concentrations of airborne radon during the collection of the calibration data. These problems may be overcome by: Testing values against expected values to flag potential problems; Deriving the height attenuation coefficient for U from the average values for K and Th if the value does not fall between those for K and Th, and; Calculating the sensitivity coefficients at various heights and plotting the K/U and K/Th ratios to reveal any radon effects. If necessary, a U sensitivity value can be obtained by appropriately scaling the Th value.