Improved Passive SAR Imaging With DVB-T Transmissions

This article investigates passive synthetic aperture radar (SAR) image formation using Terrestrial Digital Video Broadcast (DVB-T) transmitters of opportunity and an airborne receiver. The proposed airborne system does not use separate channels for direct and reflected signal reception. The proposed image formation algorithm suppresses artifacts due to the presence of the direct signal in radar echo data using modified CLEAN method and accounts for unknown irregularities in airborne platform motion using a map-drift autofocus (MDA) technique. The algorithms are theoretically derived and experimentally confirmed via an appropriate airborne campaign, and their experimental performance is measured.

I. Introduction

Passive bistatic radar has been attracting much attention in the past few decades. In using non-cooperative illuminators of opportunity, such systems have several characteristic advantages compared to active radar, including cost effectiveness, silent operation, no need for frequency allocation and licensing, and a reduced footprint in terms of electromagnetic pollution [1]–[3]. Many different types of available signals, including FM radio [4], Digital Audio Broadcast (DAB) [5], Terrestrial Digital Video Broadcast (DVB-T) [6], and Global Navigation Satellite Systems (GNSS) [7], have been investigated for various applications, which include but are not limited to image formation, target location, moving target, and coherent change detection.