DVB-T Airborne Passive Radar: clutter block rejection

Abstract

Passive radar systems generally receive direct path, ground echoes and potential target echoes. As the first two are much more powerful than the target signals, they have to be rejected. Numerous solutions are proposed in the literature. The algorithm introduced by [1] has become a reference. Due to the airborne passive clutter spread, this algorithm faces limits. In this article, we derive two solutions in order to be able to reject a large amount of clutter and therefore to reduce detrimental secondary sidelobes. Experimental results prove that the proposed method performs only 4 dB worse than in a ground configuration.

Comparison of Correlation-Based OFDM Radar Receivers

“…a) QPSK modulation: Let us first assume the use of a unit-variance QPSK modulation, so that the matched (26) and reciprocal (27) filtering approaches are equivalent. The SINR obviously highly depends on the pulse-ambiguity functions ( 15)-( 18) and on the relative position that is observed in the range-Doppler map.…”

“…Particularly, the disturbance induced by the data symbols in the range-Doppler map, referred to as random sidelobes, or pedestal, which is commonly considered as a stochastic interference component adding up to thermal noise, has only been quantified for two filters while assuming delays up to the CP duration [26]. Furthermore, the behavior of these linear receivers in presence of ground clutter have mostly-but not exclusively (e.g., see the recent work [27])been observed in terrestrial PBR scenarios, in which clutter is mainly static and quite localized in range.…”