Estimation of target motion parameters from dual-channel SAR echoes via time-frequency analysis

The paper deals with the estimation of the target motion parameters from a dual-channel SAR system. A space-time filter is required before the estimation to cancel the strong clutter echoes. It is shown that this filter does not affect the estimation based on Wigner-Ville distribution and Wigner-Hough transform (WHT) except in the presence of targets with high along-track velocity, as for fast moving objects with trajectory normal to the SAR path. In this case the cancellation filter produces an ambiguity in the WHT. A simple processing technique is proposed to compensate for this effect, which can be implemented in terms of a combination of WHTs.