Back-projection imaging algorithm of random noise frequency modulation continuous wave SAR

Abstract

The combination of random noise frequency-modulation continuous wave technology and synthetic aperture radar (SAR) promises a cost-effective, low probability of intercept and high electromagnetic compatibility. This paper analyses the time-domain restricting algorithms for random noise frequency modulation continuous wave (RNFMCW) SAR. Two versions of the back-projection algorithm are proposed. At first, the radar antenna continuous motion in a pulse repetition period of RNFMCW SAR is analysed. Then the phase term which is caused by the continuous motion is described by a approximate expression with Taylor expansion. Meanwhile, both the start-stop approximate back-projection algorithm and the modified back-projection algorithm are proposed. In the end, with the help of numerical simulation, the limitations of the start-stop approximation back-projection algorithm and the validity of the modified back-projection algorithms are illustrated.