Signal and Image Processing Algorithms for the U.S. Army Research Laboratory Ultra-wideband (UWB) Synchronous Impulse Reconstruction (SIRE) Radar

摘要

The U.S. Army Research Laboratory (ARL), as part of a mission and customer-funded exploratory program, has developed a new low-frequency, impulse- based, ultra-wideband (UWB) synthetic aperture radar (SAR), which has been used as a test bed to support proof-of-concept demonstration for detecting concealed targets. The radar is intended to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on the synchronous impulse reconstruction (SIRE) technique, which uses several relatively slow and inexpensive analog-to-digital (A/D) converters to sample the wide bandwidth of radar signals. This report first briefly describes the key radar features directly related to the signal and image processing. The main section includes the signal processing steps to clean up noise and artifacts in radar data, and the image formation technique that SIRE employs. The report also details the Recursive Sidelobe Minimization (RSM) technique (patent pending), which was integrated with the standard SAR image formation algorithm to achieve a significant reduction in sidelobes and noise in the resulting SAR imagery. Finally, the report shows sample SAR images (in both forward-looking and side-looking modes) from recent experiments.