
TY  - JOUR
A1  - Craig, M. 
A1  - Dickson, B. 
A1  - Rodrigues, S. 
T1  - Correcting aerial gamma-ray survey data for aircraft altitude
JF  - Exploration Geophysics
JO  - Explor. Geophys.
Y1  - 1999
VL  - 30
IS  - 4
SP  - 161
EP  - 166
KW  - 
UR  - https://doi.org/10.1071/EG999161 
N2  - In their ascent to the aircraft detector system, the gamma-rays recorded in airborne radiometric surveys are attenuated, first by the surface materials wherein they originate, then by the intervening atmosphere. Increased ground-clearance thus entails reduced count-rates. It also implies diminished spatial resolution, because the same cone of incident radiation derives from progressively larger ?footprints? that, for a given sampling rate, increasingly overlap. But suitable post-processing of the gridded, two-dimensional imagery can be used to correct these types of height-dependent degradation and hence produce sharper, quantitatively useful maps of radioactive isotope distribution. An essential prerequisite for such inverse filtering is noise-suppression, achieved here through maximum-noise-fraction (MNF) transformation of multi-channel data. High-frequency noise amplified by the deconvolution step is brought under control by a variant of Wiener filtering. The combined de-noising and deconvolution process is illustrated by application to an airborne gamma-ray survey from the Marble Bar area, Western Australia. 
ER  -

