Estimating hydrogeologic parameters from radar data

Radar reflections for a layered medium are dependant on the dielectric constants of the layers, which is closely linked to saturated porosity, and more loosely to hydraulic conductivity. Radar data have been obtained at a site where hydraulic conductivity has been measured in great detail. The radar cross section from the site clearly shows layering within the section, and it is tantalizing to predict that the hydraulic conductivities also persist along the bedding surfaces. The radar trace may be converted to a band limited pseudo-dielectric constant log by the same methods used to estimate an acoustic velocity log in seismic work. Thus, the resulting dielectric constant section can be converted to pseudo-porosity and pseudohydraulic conductivity displays. But, because of the limited bandwidth of the radar signal, it is tricky to invert the radar traces to yield dielectric constant and ultimately hydraulic conductivity. The main computations are 1. deconvolution with Seismic Unix routines and 2. conversion to dielectric constant including filtering to minimize numerical instabilities.