Combining resistivity-depth models obtained from the inversion of airborne electromagnetic data can be challenging, but spatially coherent resistivity-depth images of the ground can assist geological interpretations. We use ground EM data to standardise AEM data so as to be able to combine overlapping AEM datasets acquired with different systems.

This paper presents the experimental design and modelling of self-potential anomalies produced by a sphere-shaped copper–zinc source using a water tank and polarising electrodes. Self-potentials were measured by placing the sphere at a given depth in a rectangular glass tank filled with water.

In this paper, I propose to use a space-varying median filter (SVMF) to remove blending noise. I demonstrate that this filtering method preserves more useful seismic reflection than does the conventional version of a median filter (MF). SVMF can be regionally adaptive, instead of rigidly using a constant window length through the whole profile for filtering.

This paper examines anisotropic prestack Kirchhoff migration using the pseudo-acoustic wave equation in a vertical transversely isotropic (VTI) medium. Both amplitudes and traveltimes were calculated efficiently for migration using the suppressed wave equation estimation of traveltime (SWEET) algorithm.

We expand the vertical transversely isotropic generalised screen propagator into a tilted transversely isotropic generalised screen propagator (TTI-GSP) by adopting tilted coordinates. The validity of the developed algorithm has been tested by increasing the accuracy of wide-angle propagation in TTI-GSP with high-order expansion of the velocity perturbation.

We propose a process to effectively use the modified shortest path method for extracting the maximum amplitude around the first-arrival events. Then, the excitation amplitude imaging condition is applied to obtain a continuous and clear migration image. Numerical tests show that the improvement is feasible and effective in complex-structure media.

In this paper, the spherical harmonic series of the gravitational potential and its gravity field due to a right vertical cylinder was developed. This series can be used at far and intermediate regions, and it is fast and accurate, using only a few terms.

A small-loop EM survey and electrical resistivity survey were applied to a carcass disposal site to delineate the burial shape and extent of leachate arising from the burial. The small-loop EM survey was adequate for a reconnaissance survey of the burial zone and the resistivity survey was useful for quantitatively interpreting the pathway of leachate flows in the site.

The application of both geophysical imaging and geotechnical testing in road foundation design is a cost-effective enhancement for site characterisation of soft soils and for risk assessment of potentially unstable embankments. The incorporation of geophysics allows concentration on fewer but higher quality soil probings and geotechnical boreholes.