A Distributed Radar Sounder Concept for Subsurface Exploration of Saturn's Moon Enceladus: Feasibility and Potential

• DOI: 10.5194/egusphere-egu25-21319
• Publication Date: 2025-03-15T06:29:37Z
• Authors: Andreas Benedikter; Ana-Catalina Plesa; Jalal Matar; Hauke Hussmann; Masaki Nagai; Tobias Otto; Taruna Parihar; William Byrne; Tina Rückriemen-Bez; Eduardo Rodrigues...; Gerhard Krieger; Marc Rodriguez-Ca...
• Keywords: Enceladus

Since the very first observations of Moon, radars have been more and employed as payloads planetary exploration missions, in various operational modes like altimeters, SARs or radar sounders. Especially sounders provide unique measurement capabilities for subsurface bodies, demonstrated by MARSIS SHARAD instruments planned REASON [1] RIME [2] Europa Clipper Juice aimed on Jupiter’s icy moons. Radar are nadir-looking sensors that transmit pulsed electromagnetic radiation propagates through due to its relatively low frequency. Each dielectric discontinuity ground material reflects part signal towards radar. The analysis recorded echoes provides crucial information structure composition. Despite capability achieving good performances, abovementioned limited almost omnidirectional antenna characteristic dipole antennas commonly used because large size at frequencies. Due characteristic, surface clutter, i.e., spurious signals from off-nadir directions, is collected potentially masks interest coming layers nadir direction, thus hindering data interpretation.To overcome those limitations, we investigate feasibility potential a distributed sounder satellite configuration an Enceladus mission scenario, frame ESA study. Distributed sounding configurations already proposed Earth Observation regions (e.g., STRATUS concept [3]). Such formation flying allows synthesizing array following advantages with respect traditional configuration: 1) suppress clutter beamforming techniques, 2) increase noise ratio, 3) possibility exploiting interferometric techniques DEM generation interpretation, 4) performing 3D tomographic imaging subsurface.We present HF-band including science case derivation, orbit implications, concepts, instrument system architecture 5) performance assessment. consists up 7 satellites, one complex mother (~1.5 tons) implementing transmission other power mass demanding functionalities communication, down-link, storage, on-board processing), satellites (~200 kg) transponder receive forward it MirrorSAR [4] configuration. A main criticality strongly perturbed gravitational environment [5] posing challenges orbits capabilities. Potential concepts presented well assessment based envisioned formation, attenuation backscatter models, different approaches.References:[1] Blankenship et al., 2009. Bruzzone 2013. [3] 2021. Krieger 2017. Benedikter 2022.