Airborne THz SAR Imaging Using RD Algorithm Integrated with Autofocus

This paper presents a process of imaging airborne THz radar data based on RD(Range Doppler) Algorithm. Because of the motion error which would effect the imaging quality, this paper we adopt autofocus to compensate motion error. People usually use the motion parameters measured by GPS to compensate the motion error. However the precision of the motion parameters can not satisfy the requirement and the millimeter-band SAR is more sensitive to motion error, thus the traditional compensate method is not useful. To solve the problem people adopt autofocus. In this paper we adopt MDA(Map-Drift Algorithm) and PGA(Phase gradient autofocus) to compensate the motion error. And we make a comparison with the imaging result without autofocus and the imaging result with autofocus to examine the effect of autofocus.