Wideband echo simulation and velocity compensation of midcourse ballistic target

Ballistic missile target (BMT) in midcourse possesses two motion features of high velocity and micro-motion. The measured Doppler shift is ambiguous and modulated by the micro-Doppler components. It is difficult to estimate the micro-Doppler bandwidth of BMT and extract its micro-motion parameters. Under the condition of taking account the motion features of BMT, its wideband echo mathematical model is established and investigated at first. Then, the velocity compensation technique is put forward which is based on simplified fractional Fourier transform (SFRFT), Particles Swarm Optimization (PSO) and minimum entropy theories. Simulation results show that the advanced method can present accurate parameter estimation and perform effective compensation for translation Doppler shift. Even in low signal to noise ratio (SNR) case, the simulated outcomes prove it still work well. This technique provides the precondition for micro-Doppler feature extraction.