Micro-Doppler Signal Decomposition Using Second-Order Vertical Synchrosqueezing

The concept of using second-order vertical synchrosqueezing (VSS) in the time-frequency (TF) domain for the decomposition of the micro-Doppler signal is described in this paper. In general, the technique aims at sharpening the energy distribution on the TF plane, but contrary to the known reassignment method, allows one to retain phase information and reconstruct the signal or a distinguished component, which favors analysis of multi-component waveforms such as micro-Doppler signatures. Theoretical considerations are briefly described and then an implementation of the technique and its application in order to analyze a real-life micro-Doppler signal is presented. Numerical validation shows that the second-order VSS and an algorithm that serves to extract signal modes can be efficiently used in signal decomposition and target description.