Lithospheric flexure. In a nutshell, this field concerns estimation of the elastic thickness (Te) of tectonic plates, which is a measure of their strength, or resistance to loading, say from volcanism, mountain-building, or sedimentation. One way to estimate Te is by correlating gravity and topography in the spectral domain, and then inverting the resulting coherence against theoretical models of plate flexure. Hence the research is a combination of geophysics, geodesy, mechanical engineering, and signal processing.
While the Fourier transform may be used to do the spectral analysis, I prefer to use the wavelet transform, which also forms a large part of my research. As well as writing journal articles on wavelets, I have written software to compute the continuous wavelet transform which has been used by many groups worldwide.
My other research topics fall under the category of physical geodesy, such as geoid determination, Earth and planetary gravity fields, gravimetric terrain corrections, and satellite altimetry.