Considerations for Non-cooperative Bistatic SAR with Spaceborne Radar Illuminating

Bistatic radar, especially illuminating of opportunity, has recently been one of interesting research hotspot due to its military stealth and economic advantages. In this paper, we consider non-cooperative bistatic SAR using aircraft as receiver and spaceborne radar as illuminating of opportunity. Firstly, we qualitatively descript the relationship between geometry and resolution of bistatic SAR. Then, we study receiver geometry configuration from imaging resolution and receiving data aspects. Theoretical analysis shows that observation time has relation with the azimuth initial position of receiver beam footprint, which is relative to transmitter beam footprint, and footprint velocity of transmitter and receiver respectively. Through example calculation, we find that observation time have weak relation with the aircraft velocity and strong relation with the azimuth initial position of receiver beam footprint, which is relative to transmitter beam footprint The imaging area mainly depends on observation time and aircraft velocity and receiver main lobe beamwidth. Finally, simulations demonstrate that non-cooperative bistatic SAR system, in our case, can possess a short observation time range (l-3s)