Radar Sounder in Interplanetary Mission: Hybrid EMC Verification Approach

The use of HF radar sounders for planetary exploration creates a substantial challenge with the electromagnetic emissions generated by modern spacecraft platforms and payloads. This paper reviews systemic EMC challenges in such missions, highlighting how stringent scientific requirements necessitate the tailoring of generic ECSS limits to ensure mission success. The fundamental physical limitations of pre-launch validation are analyzed, specifically the geometric constraints of anechoic chambers regarding large dipole antennas (16-40 m), the performance of the absorbing materials, and the inability to replicate the spacecraft’s role as an electrically active part of the radiating system. By examining documented discrepancies between ground verification and in-flight behavior, this work exposes the complexity and limitations of current ground-based EMC testing for radar sounders, highlighting the urgent need to develop novel verification techniques to accurately predict the operational performance of such low-frequency radar sounders.