Filtering approaches for interference suppression in low-frequency SAR

Abstract

Low-frequency synthetic aperture radar (SAR) systems are of interest primarily because of their ability to see through foliage for a variety of purposes. Unfortunately, the very high frequency/ultra-high frequency bands are used by a large number of services such as television, radio and communications. The authors describe a number of different radio frequency interference suppression techniques that have been investigated and that were tested on wide bandwidth low-frequency SAR data collected on board a helicopter using the Airborne Data Acquisition System (ADAS) low-frequency radar. The least-mean-square (LMS) filter and the Wiener filter are both investigated in detail. The adaptive Wiener filter is found to have superior suppression and sidelobe performance and is also computationally much faster than the LMS filter when applied to the ADAS data.