Design and processing of a self-mixing passive forward scatter radar fence for space debris tracking

The goal of space domain awareness (SDA) is to maintain the safety of communication and navigational processes within the space environment. This includes the tracking of space debris targets which possess high enough velocities to destroy satellites and jeopardize the lives of astronauts. Current technologies tasked with space debris monitoring employ large, quasi-monostatic arrays using S-band probe signals. To reduce cost, alleviate spectrum congestion, and expediate deployment, this paper proposes a self-mixing passive radar technique applied to multiple targets and sensors for identifying the Doppler signature from received signals. It was found that the self-mixing technique can isolate the Doppler signal in the single target case, and the Doppler signals along with Doppler difference signals in the multi-target and multi-sensor cases. In addition, a discrete, integer relationship exists between the Doppler signature at different receivers and is shown to occur when one of the receivers loses Doppler resolution.