Echo Data Acquisition Method based on Variable Sampling Threshold for Ultra-high Resolution SAR

Due to the significant range cell migration (RCM), the sampling data of the echo signal will be huge for ultra-high resolution synthetic aperture radar (SAR) imaging, which brings difficulties to data storage and processing. For this problem, an echo data acquisition method based on variable sampling threshold is proposed in this paper. During the data acquisition interval, the sampling threshold is periodically changed according to the variation of the distance between the radar and the target. Therefore, most of the RCM can be compensated during the data acquisition, which will greatly reduce the amount of the sampling data. In addition, only phase compensation is necessary to recover the signal in the data process. Thus, it does not need to change the imaging processing procedure. Simulation and real data results are used to validate the effectiveness of the proposed method.