Correlation-based imaging of fast moving objects using a sparse network of passive receivers

We consider the problem of imaging small fast moving objects. The imaging system consists of a powerful emitter (X-Band) located on the ground and several passive receivers. The study of imaging fast moving objects is motivated by the need to detect, track and image small energetic debris (1-10cm) revolving around the earth at a low orbit (200km-2000km). This is of interest because of the large amount of debris which substantially increases the risk of satellite damage from collisions. To determine the location and the velocity of the object we use correlation-based imaging because it has been shown to be robust to medium fluctuations such as atmospheric lensing and aberrations. We show that with only about 9 recording platforms we get as good a resolution as if we had a full '100 x100 kilometer aperture.