High Range Resolution with digital stretch processing

This paper describes an approach to high range resolution (HRR) by means of stretch processing by digital deramping. This approach offers advantages that are common for stretch processing, as a moderate data rate for signal processing in the presence of a high bandwidth waveform. In contrast to conventional analogue processing, deramping is realized digitally. The approach of digital deramping offers the possibility to combine the deramp processing with digital down modulation. Moreover, the digital deramping allows to measure and calibrate distortions in the analogue radar front-end. A calibration scheme is presented that incorporates calibration corrections into the digital deramp signal. The calibration scheme is of particular interest for applications in active phased array radars with multiple receive channels. The presented approach offers a number of advantages compared to analogue stretch processing and other approaches to high range resolution.