BEM Reference Signal Estimation for an Airborne Passive Radar Antenna Array

Abstract

In this article, we consider an airborne passive radar using DVB-T OFDM signals. In such an application, the channel composite nature and the mobility of the receiver deeply alter the signal and therefore degrade the decoding processing. Classic methods experience difficulties in dealing with such channel impacts. In order to reconstruct a proper reference signal, we propose here a channel estimation method that exploits both antenna diversity and a Basis Expansion Model (BEM) modeling the channel time-variations. The application of this method to experimental in-flight recorded data demonstrates the performance improvement provided by the proposed method over the classic demodulation and other methods developed to cope with InterCarrier Interferences (ICI).

DVB-T Airborne Passive Radar: clutter block rejection

“…It then becomes our reference signal, denoted as s ref . This estimation may be easy for terrestrial non moving platform, but reveals to be much more difficult in case of an airborne platform as precised in [12]. Then, direct path and clutter have to be rejected.…”

Improved Passive SAR Imaging With DVB-T Transmissions

“…[25]) algorithms may be an essential part for passive surveillance radar using DVB-T to compensate for ambiguities due to pilots, they may not be necessary (although optimal) for DVB-T SAR purposes. In this case, a substantially reduced algorithm complexity would be achieved, especially taking into account Doppler spread on OFDM due to SAR platform motion [26], at the cost of a sub-optimal performance which requires a dedicated study beyond the scope of this paper.…”

Passive SAR satellite (PASSAT) system: airborne demonstrator and first results

“…Crucially, the latter method is especially relevant to PASSAT, and might be the only option for providing range compression. First of all, decoding the direct signal from a fast‐moving platform such as a satellite is not a first option due to the fact that multipath signals entering the reference channel will have a different Doppler shift from the direct signal which upsets an attempt to decode the signal [24]. Secondly, it has been calculated that for a sufficiently high SAR sensitivity, a receiving antenna of 15 dB gain can be deployed from a nano‐satellite [20].…”