Observations of planetary surfaces obtained at radio frequencies (RF) allow us to study the material properties and structure of the surface and shallow subsurface. RF measurement techniques include transmission and reception of scattered signal, as well as passive reception of emitted signal. The data collected provides information about the subsurface anywhere from depths of a few centimeters to a few tens of meters, subject to signal characteristics (such as bandwidth, polarization), target properties, and observation geometry. We work with RF measurements collected at MHz to GHz frequency range from ground-based, airborne, and spaceborne platforms to study regional geology and stratigraphy on other solar system objects.

Radar wave propagation and scattering

Retrieving useful information from the RF data requires thorough description of how the RF signal interacts with the target. We develop radar wave propagation and scattering models to characterize interaction between geologic media and radar waves. These models are specifically helpful in scientific interpretation of multi-wavelength and multi-polarization data.

Surface characterization

We use GHz data from ground-based telescopes and spacecraft to study the surface on Venus, including roughness and dielectric properties of volcanic terrains, "metal frost" covered highlands, and fine-grained material generated by impact cratering and volcanism. We are also interested in strategies for radar-based and radiometric detection of potentially ongoing magmatism on Venus. We use radar wave scattering and emission models to characterize RF returns from actively cooling lava on Venus.

Subsurface imaging

Multiple sounding radars on missions to Mars have provided observations of the surface and subsurface. We use these RF measurements at MHz frequencies, obtained from both spacecraft and rovers, to reconstruct the subsurface geology of volcanic, icy, and paleo-aqueous environments on Mars.