Abstract DGP2026-110

An ultra-wideband ground-penetrating radar (GPR) system has been developed for the integration into small planetary rovers, landers, or CubeSats intended for future lunar and Martian exploration missions. The instrument was designed and tested to archive key scientific objectives, including the characterization of near-surface stratigraphy, detection of subsurface ice and cavities, and mapping of geological structures relevant to planetary evolution and in-situ resource utilization (ISRU). It’s extremely compact electronics, occupying less than half a CubeSat unit, operates across a frequency range of 10 MHz to 6 GHz, enabling high-resolution imaging over varying penetration depths. The system has two independent transmit and two independent receive channels, allowing simultaneous full-polarimetric measurements to enhance material differentiation beneath the surface.

The radar uses a Frequency-Modulated Continuous-Wave (FMCW) architecture and offers highly flexible operations, for example through flexible measurement speed settings and an advanced gating to improve the system’s dynamic range, particularly for deep subsurface investigations. Depending on the antenna configuration, platform integration, and local geophysical properties, the radar can probe depths of tens of meters, while achieving centimeter-scale resolution in near-surface layers. Due to its high sensitivity, it is particularly well suited for detecting ice-rich regolith and buried pockets of water ice, as the contrast between ice and regolith produces clearly visible radar reflections.

Particular attention is currently being paid to the permanently shadowed regions (PSRs) at the South Pole of the Moon – areas that have not received sunlight for billions of years. These regions and the partially shadowed areas, which have complex light and temperature conditions, act as cold traps for water ice, which is crucial for future human exploration and resource utilization.

This GPR system will be integrated into a small rover called Rashid as part of a future United Arab Emirates lunar mission. The instrument, called Deep Regolith Sounder (DRS), will map subsurface structures, determine the thickness of the regolith layer, and detect the presence of water ice at depths of several tens of meters. DRS consists of compact radar electronics and a lightweight, flat, linearly polarized antenna mounted under the rover. The antenna, which covers a frequency range from 200 MHz to 6 GHz, weighs less than 200 grams. Its performance is affected by frequency-dependent coupling with the rover structure and variations in the dielectric properties of the regolith, requiring advanced signal processing and calibration algorithms to mitigate these effects and improve spatial resolution despite the small dimensions of the antenna and rover.

Field tests in glacial and permafrost regions of Svalbard have shown that DRS is capable of achieving a sufficient signal-to-noise ratio for subsurface imaging and estimating losses of lunar regolith. The system is well-suited for providing high-resolution subsurface data and supports both scientific research and the planning of further future robotic and manned lunar missions.