Graduate Seminar with Chao Liu: Influence of Antenna Pattern on Synthetic Aperture Radar Resolution for NDE Applications


September 1, 2021    
1:10 pm - 2:00 pm


3043 ECpE Building Addition
Coover Hall, Ames, Iowa, 50011

Event Type

Speaker: Chao Liu, ECpE Graduate Student

Advisor: Reza Zoughi

Title: Influence of Antenna Pattern on Synthetic Aperture Radar Resolution for NDE Applications

Abstract: The effect of antenna gain pattern on synthetic aperture radar (SAR) imaging is analyzed in this work. In prior investigations, only the effect of antenna half-power beamwidth (HPBW) on the resultant image spatial resolutions were described using approximations that are valid only at very large distances or at small distances with relatively wide HPBW. This work illustrates that this approximation is not valid in the near-field of the synthetic array when the antenna used is highly directive. In this work, the effect of the entire antenna (gain) pattern, instead of just assuming a constant pattern within the HPBW, on SAR image spatial resolutions (both range and cross-range) is demonstrated. Additionally, the effect of approximations which are necessary for implementing fast Fourier transform (FFT)-based algorithms (e.g., ω-k SAR algorithm) on the image resolutions are also studied. The concept of effective synthetic aperture length is introduced and corresponding empirical formulas are derived. Subsequently, this effective aperture length is used to calculate the image spatial resolutions. Finally, representative measurements were performed to verify the simulation results.

Bio: Chao Liu (Graduate Student Member, IEEE) received his B.S. degree in Electronic Information Engineering from Xidian University, Xi’an, China, in 2014, and his M.S. degree in Electromagnetic Field and Microwave Technology from Southeast University, Nanjing, China, in 2017. He is currently pursuing his Ph.D. degree in Electrical Engineering at Iowa State University (ISU), Ames, IA, USA. He was a Ph.D. candidate in Electrical Engineering at Missouri University of Science and Technology from 2018 to 2019, prior to transferring to ISU. His current research interests include microwave and millimeter wave imaging, antenna design, and materials characterization.