Bistatic forward-looking SAR imaging based on two-dimensional principle of stationary phase

Synthetic aperture radar (SAR) techniques are typically used to achieve a high azimuth resolution, but conventional monostatic SAR is not applicable in forward direction because of azimuth ambiguities and poor Doppler resolution. In this paper, we present a new bistatic forward-looking SAR imaging algorithm based on point target reference spectrum using the two-dimensional (2-D) principle of stationary phase to improve the Doppler resolution and to avoid azimuth ambiguities. Based on the bistatic configuration and the novel algorithm, SAR not only can image the forward-looking terrain of the aerocraft, but also plays sufficient role in selflanding and navigation. Finally, simulations are used to validate the proposed spectrum and processing algorithm.