Airborne radiometric calibration ? an Australian perspective

Abstract

Airborne radiometric systems must be calibrated to present data devoid of artefacts peculiar to their acquisition. The IAEA(1991) model of the components of airborne radiation is outlined. This features: aircraft background radiation; cosmic-effect (related to survey altitude); Stripping Ratios which account for the spectral overlap of radiation from different radioelement sources; and height attenuation coefficients, which quantify the effect of Compton Scattering of gamma rays passing through the air. Resources of calibration pads and radiometric test range sites are listed. The facets of calibration procedure are discussed according to their application to the IAEA model. The resulting calibration parameters are used in a process to generate airborne radiometric system sensitivities by comparison of airborne and ground spectrometer data. This method can avoid errors in system sensitivity caused by environmental factors.