A Particle Filtering Model Using Instantaneous Range for Vibration and Nonlinearity Compensation of Triangular FMCW Ladar Signal.

The frequency modulation continuous wave (FMCW) Laser radar (Ladar) inevitably suffers from vibration and nonlinear modulation, which will reduce ranging accuracy and imaging resolution. We propose a vibration and nonlinearity compensation method using particle filtering (PF) for one- period triangular frequency modulation continuous wave (T-FMCW) signals. We first extend the traditional ranging model to an instantaneous ranging model by a second-order synchro-squeezing transform (SST) which can characterize the local distributions of time-varying signals. We then eliminate the nonlinearity errors from the instantaneous measurement ranges by setting an auxiliary channel. Finally, we built a particle filtering (PF) model using the instantaneous ranges to compensate for the vibration and the residual nonlinearity errors, and estimate the range of target by using the triangular relations of T -FMCW. Experimental tests prove that the proposed method can accurately estimate the range of target by simultaneously compensating for the vibration and nonlinearity errors in one-period T -FMCW.