Multipath clutter cancellation and tracking algorithms for passive radars

Abstract

We demonstrate the ability of a passive radar system to monitor a large area of interest by applying advanced multipath clutter cancellation algorithm, spatial beamforming and tracking techniques. The mitigation of clutter disturbance and a two stage beamforming method facilitate real time tracking of small to moderate size targets in real Cartesian domain. The results have been validated through a real data acquisition campaign performed using an eleven element array antenna based passive radar developed at FHR Institute in Germany

Space-Time Adaptive Cancellation in Passive Radar Systems

“…In [9], the system performs the optimal MVDR beamforming in the first stage and then filters the residual direct path interference with the CLEAN algorithm. The same filtering schema can be seen in [6,15,17,18].…”

“…This filtering procedure is used in many systems [5,15,17,18]. The filtered surveillance signal for this filter scheme can be calculated as follows:…”

“…One can say that the surveillance antenna channels can be prefiltered by M individual temporal filter. In this implementation, the filtered output of the antenna channels is described by (15).…”

“…These procedures are quite different in implementation but solve the Wiener filtering problem without exception. The resulting FIR filter produces the sum of the properly weighted and delayed replicas of the reference signal, which is then subtracted from the surveillance channel [9][10][11][12][13][14][15][16].…”

“…In this processing setup, the standard temporal filter precedes the beamformer. Thus, the surveillance antenna channels x s n m , m = 0, … , M − 1 are filtered individually according to (15); then, the filtered output is calculated with beamforming of the prefiltered antenna channels using (8), where x s n m is replaced by x f n m . The temporal dimension is uniformly J = K = 128 in all cases, and the MVDR beamformer uses a 83 ∘ as the steering vector to receive the target reflection.…”