Speaker: Dong Zhen

Affiliation: National University of Defense Technology (NUDT)

Academic title: Professor

Abstract:

For the airborne SAR system, turbulences during the flight can make the aircraft deviate from the ideal path, degrading the image quality, such as resolution loss, contrast reduction, and  sidelobe unblancing. This detrimental effect is particularly pronounced in very-high-resolution (VHR) SAR systems due to the strong two-dimensional (2-D) space-variant  characteristics of motion errors. 

In this report, we first propose a motion compensation (MoCo)  method that completes range-variant  envelop error and 2D-variant azimuth phase error compensation before  range cell migration correction (RCMC). This method is based on non-approximate motion error expressions and can fully utilize the  trajectory information. 

Then, a robust autofocus algorithm is proposed, which takes into account both the residual range-variant envelop and phase errors. Simulations demonstrate that our proposed algorithm can achieve high-quality images. And a X-band  (0.1m*0.1m) airborne stripmap SAR data are analyzed to verify the effectiveness of the proposed framework.

Biography:

Zhen Dong was born in Anhui, China, in September 1973. He received the Ph.D. degree in electrical engineering from National University of Defense Technology (NUDT), Changsha, in 2001. He is currently a Professor with the College of Electronic Science and Engineering, NUDT. 

His recent research interests include SAR system design and processing, Ground Moving Target Indication (GMTI), and very-high-resolution SAR imaging.