A calibration procedure for airborne gamma ray snow surveys

TitleA calibration procedure for airborne gamma ray snow surveys
Publication TypeConference Proceedings
Year of Conference1980
AuthorsGlynn, J. E., and Grasty R. L.
Conference Name48th Annual Western Snow Conference
Series TitleProceedings of the 48th Annual Western Snow Conference
Date PublishedApril 1980
PublisherWestern Snow Conference
Conference LocationLaramie, Wyoming
KeywordsGamma ray snow survey, Remote sensing

Using an airborne gamma ray spectrometer, nine pre-snow and nine snow flights were carried out at different altitudes over a site in eastern Ontario, based on air attenuation coefficients, snow-water equivalents were calculated for the total count (0.41 - 2.81 Mev), potassium (1.36 - 1.56 Mev), and thorium (2.41 - 2.81 Mev) windows. An iterative procedure incorporating height dependent stripping ratios was used to correct for Compton scattering in the snowpack and in the air. Soil moisture corrections were also applied. The standard deviation in the calculated snow-water equivalent from the total count, potassium, and thorium windows for the nine snow flights had values of .1, 1.2, and 1.3 cm water respectively and the results agreed with ground measurements of 14 +/- 3 cm.