Spaceborne/airborne bistatic synthetic aperture radar focusing on an analytical bistatic point target reference spectrum

An analytical bistatic point target reference spectrum (BPTRS) is proposed. The BPTRS is derived from the one-to-one relationship between slow time and Doppler frequency with no Taylor series expansions. Based on the BPTRS, a twodimensional frequency-domain focusing algorithm for spaceborne/airborne bistatic synthetic aperture radar is developed. The algorithm exploits a range-dependent sub-blocks processing method to perform range cell migration correction and quadratic Doppler term compensation, and then a scaled inverse Fourier transformation and a sinc interpolation are used to correct the geometric distortions in azimuth and range, respectively. Some simulation experiments are also presented to verify their performance.