“…The use of the airborne gamma-ray spectrometry and altimetric data in regolith studies must be investigated, especially when applied with mathematical techniques, raster image algebra, and in the evaluation of multi-source data (e.g., Darnley and Grasty, 1971, Tucker et al, 1984, Duval, 1990, Burrough et al, 1992, Graham and Bonham-Carter, 1993, Wilford et al, 1997, Dickson and Scott, 1997, McKenzie & Ryan 1999, Zhu et al, 2010, Carrino et al, 2011, Wilford, 2012and Dent et al, 2013.…”