Effective Motion Compensation of THZ SAR Imaging Based on Range Sub-Band Conjugation

High precision and high efficiency motion error compensation is a very challenging work for Terahertz synthetic aperture radar (THz-SAR) imaging, the tiny vibration of platform will make seriously THz-SAR image defocused. In this paper, a new compensation method based on the division of range sub-band conjugate, name as SBCM, is presented for THz-SAR effective motion correction. In the scheme, we use image entropy to iterate the overlap rate of the divided range sub-bands of THz-SAR echoes, and conjugate multiplying the division range-compressed results to obtain a more ideal imaging effectively. Both simulation and experiment results demonstrate the effectiveness of SBCM method. Compared with traditional echo-derived phase estimated autofocusing method, SBCM method not require parameter estimation and its arithmetic is small.