A modified bistatic point target reference spectrum for bistatic highly squint SAR processing

2-D spectrum of bistatic highly squint SAR is skew, which increases the cross coupling of spectrum between range and azimuth. To correct the skew phenomenon brought by highly squint mode of transmitter and receiver, the linear range walk of echo signal is corrected in range frequency and azimuth time domain, then a modified bistatic point target reference spectrum for bistatic highly squint SAR processing is derived using the Method of Stationary Phase. Simulations show that the modified bistatic point target reference spectrum can correct the skew phenomenon of the 2-D spectrum and decrease the degree of coupling between range and azimuth, the good focusing performance of modified spectrum for bistatic highly squint SAR processing is also verified.