Complex trajectory millimeter-wave InSAR interferometry using maximum sharpness BP autofocusing algorithm

Due to platform uncertain motion, the trajectory of airborne millimeter-wave interferometric synthetic aperture radar (MMW-InSAR) usually demonstrates highly non-linear associated with position errors. Hence, motion compensation must be considered for airborne MMW-InSAR high resolution imaging. In this paper, a back projection (BP) autofocusing algorithm via maximum sharpness is presented for MMW-InSAR interferometry in the case of complex trajectory with motion errors. In the scheme, the MMW-INSAR data is focusing by BP along the complex trajectory, and the azimuth phase errors is estimated from the dominant scatterering area using an iterative procedure, which aims to maximizing the InSAR image sharpness. The effectiveness of the proposed method is testified by the experiment data, the results demonstrate that it can improve MMW-InSAR imaging quality compared with conventional BP algorithm in the case of complex trajectory.