Radon Transform and Its Applications in Gridding Airborne Geophysical Survey Data

摘要

The Random transform method has been studied as a means of presentation ofgeophysical data, and in an attempt to develop a better gridding technique for line-based airborne geophysical data. The observed line-based data are usually spatially aliased because the line spacing is too large compared with the wavelength of features in the cross-track direction. Another problem for conventional gridding methods is that they tend to destroy the continuity of elongated anomalies whose strike direction is not perpendicular to the grid-line direction. The radon transform gridding method transforms the observed parallel profiles into the strike-wavenumber domain. The Fourier spectrum of the desired grid is constructed from the strike-wavenumber domain using projection-slice theorem, and the final square grid is obtained by performing an inverse Fourier transform of the spectrum. Hence, two interpolations must be made in the application of the method to line-survey geophysical data: the first one is during transforming the observed parallel profiles into the strike-wavenumber domain, and the second one during the inverse process.