Multiframe Track-Before-Detect of Weak Fluctuating Targets in a Complex-Valued RD Plane

The use of track-before-detect (TBD) of weak fluctuating targets is significant in radar systems. Conventional TBD methods may suffer from model mismatch and information waste, and the target fluctuation may not be considered. In this paper, to improve the detection and tracking performance of weak fluctuating targets using complex-valued range-Doppler (RD) data, a multiframe TBD method is proposed in a complex-valued RD plane. The target state evolution in the RD plane is formulated for multiframe accumulation accuracy. Considering the additional phase of raw complex-valued RD measurements, matched filtering based TBD using both amplitude and phase information in the raw RD plane is presented. Five common fluctuation models, i.e., Rayleigh distributed model, x2 distributed model, Log-Normal distributed model, Weibull distributed model, and K distributed model are used to describe the target fluctuation in RD plane. The procedure for multiframe accumulation of fluctuating targets in RD plane is presented in detail. The multiframe accumulated envelope of the fluctuating target in RD plane is derived theoretically, and the computational complexity of the proposed method is also analyzed. Both numerical simulations and real data are used to demonstrate the effectiveness of the proposed method