Analysis of Micro-Doppler Signatures for Radar Targets Based on Higher Order Time-frequency Distribution

Target characteristic with micro-motion depicts the target details detailedly, therefore it can provide a new way for radar target measurement and its recognition. On basis of analyzing the micro-Doppler laws of several typical targets with micro-motions, such as the maneuvered point target, the vibrational point target, the composite moving point target and so on, the paper proposed an algorithm to analyse the target micro-Doppler features using the modified L-Wigner distribution from the angle of higher order time-frequency analysis, analysed the measure to improve the time-frequency concentration and the measure to eliminate the cross-terms as well as its efficient recursive calculation method in detail, and then gave out the complexity analysis for the proposed algorithm. At last the algorithmic simulations were performed by taking the maneuvered point target, the vibrational point target, the composite moving point target and the group target containing multiple point targets as examples. Simulation results show, comparing with the linear time-frequency representation and the Cohen class bilinear time-frequency distribution, the proposed algorithm can gain better time-frequency concentration for a complex nonlinear modulation target echo signals, and better eliminate the influence of the cross interference items, and at the same time it has a smaller algorithmic calculation burden.