ISAR imaging in strong ground clutter using a new stepped-frequency signal format

In this paper, a new easy-to-implement variant of the stepped-frequency signal format is presented for ground clutter cancellation application. A sequence of pulse-groups, where each pulse-group consists of two pulses of the same carrier frequency, is transmitted. The carrier frequency of each subsequent burst is stepped at Δf. Simple first-order cancellation of ground clutter can be carried out by comparing the returns of the two adjacent pulses, as the clutter movement (due to wind, etc.) can be assumed negligible within this interval (typically <1 μs). A computer simulation is given to illustrate the effectiveness of the proposed method.