A Spaceborne Multistatic Radar Sounding System for the Tomographic Observation of Polar Ice Sheets

Radar sounding plays an irreplaceable role in polar ice sheets research. Over the past 60 years, vehicle-borne and airborne systems have provided large amounts of topographic data on ice sheets. However, due to the limitations of atrocious weather in the polar regions and the platform operating distance, a large blind zone of observations still remains. Spaceborne radar systems can realize efficient observations of the Earth's surface due to the wide swath of satellites and the penetration of clouds and rain by microwaves. However, existing remote sensing satellites still cannot observe ice beds, which are subject to severe radio attenuation and complex signal propagation in ice. In this article, a spaceborne multistatic radar sounding system named the BingSat-Tomographic Observation of Polar Ice Sheets (TOPISs) is proposed to achieve high resolution and stereoscopic observation. Over the polar regions, the satellite formation design via passive CubeSats with dipole antennas forms a large cross-track baseline. Based on that, cross-track resolution improvement, ice attenuation compensation, and surface clutter suppression are realized simultaneously. Single-input and multiple-output mode and MirrorSAR technology are employed to reduce the manufacturing cost and realize synchronization. With a high transmitting power and antenna gain, BingSat-TOPIS can penetrate several kilometers of ice sheets.