3D “Mapping” Complex Dielectric Permittivity and its Anisotropy in Planetary Materials for Improving 3D Radar Scattering Models for Future SAR instruments for Mars and the Moon

Status: Completed

Start Date: 2023-10-01

End Date: 2025-09-30

Description:

The goal of this effort is to develop and establish a new and unique, non-destructive methodology for the three-dimensional (3-D) characterization of the complex dielectric permittivity (CDP) of arbitrary shaped planetary rocks and Earth analog samples. Our work will set a path to produce the first world-class type facility for the 3-D “mapping” of the isotropic and anisotropic dielectric properties of a variety of rock and soil samples, relevant to Synthetic Aperture Radar (SAR) observations of Mars and the Moon.

Benefits:

It is expected that future missions to the Moon and Mars [Artemis, and described in 2022 Planetary Decadal Survey “Origins, Worlds, and Life”] will include orbital polarimetric L-band (or S-band) Synthetic Aperture Radars (SAR) to investigate subsurface features and volatile-enriched layers in order to identify in-situ resources including water ice deposits. The performance of these radars and the estimates derived from their measurements will largely depend on the precise knowledge of the complex dielectric permittivity (CDP) of the surface and subsurface being interrogated. Current methods employed in radar scattering analysis, retrievals, and performance prediction typically employ a “bulk” CDP measurement (i.e., from Resonant Cavity Perturbation or RCP) which can introduce significant errors in any of the radar estimates of critical parameters such as depth of penetration (Zheng et al., 2005). This is because of the intrinsic volumetric CDP anisotropy in rocks (Chizever, 2021 [PhD Thesis]), well known since the 1960’s.

Lead Organization: Goddard Space Flight Center