Research on terrain correction method of airborne γ spectrometry

Abstract

BackgroundAirborne gamma spectrometer is a method to measure ground gamma nuclide activity (specific activity) by installing gamma spectrometer on aircraft. The accuracy of results is affected by flight altitude and terrain fluctuation. At present, altitude correction has been applied to the quantitative analysis of airborne gamma spectrometer, but the correction effect of altitude correction on areas with large terrain fluctuation is not desirable.PurposeThis study aims to propose a 3D terrain correction method based on discrete integral.MethodsFirst of all, the basic characteristics of digital elevation model (DEM) and radiation field distribution were analyzed. Then, the effective detection area of airborne gamma spectrometer was divided into micro grid surface elements, and the contribution of micro elements to the counting rate of full energy peak of the airborne gamma spectrum was calculated. The terrain correction coefficient by discrete integral was realized by the terrain correction of airborne gamma spectrum measurement results, and the accuracy of airborne gamma spectrum measurement results was simultaneously improved. Finally, verification of this method was performed on the measured airborne gamma-ray spectrum data processing.ResultsVerification results show that the influence of terrain on gamma spectrum data is corrected effectively by the proposed method.ConclusionsThe 3D terrain correction method based on discrete integral can improve the consistency between airborne gamma spectrum measurement results and ground measurement results, and has the advantages of fast mesh division, altitude and terrain correction simultaneous.

Keywords

• airborne gamma-ray spectrometry survey
• terrain correction
• height correction
• inversion