基于通用复时频分布的进动目标微多普勒提取

摘要

首先建立了进动锥体目标的雷达回波模型,推导了目标微多普勒频率与进动参数的定量关系.针对进动目标雷达回波具有的多分量非线性调频特点,提出了通用复时频分布(generalized complex-time-frequency distribution,GCD)的微多普勒提取方法,与线性和二次Cohen类时频分布相比,GCD具备高时频分辨力、低交叉项的优点.同时针对峰值估计微多普勒瞬时频率(instantaeous frequency,IF)方法受信号频率交叉覆盖和噪声干扰严重的问题,提出基于Viterbi算法的微多普勒IF估计方法,有效提高了微多普勒IF估计精度.实验中利用仿真和暗室测量数据验证了GCD-Viterbi方法的性能.%The radar signal model of cone targets with precession is provided, which can develop the relationship between micro-Doppler and precession parameters. Due to the characteristics of nonlinear frequency modulated and multi-components in radar signal, generalized complex-time-frequency distribution (GCD) is introduced to analyze the micro-Doppler of targets with precession, which has better concentration and time-frequency resolution compared with that of classical time-frequency distributions. Moreover, the estimation algorithm of micro-Doppler instantaneous frequency based on GCD and Viterbi method is proposed to reduce the effect of cross-term artifacts and noise, as weIl as improve the estimating precision. The performance of the estimation algorithm is validated with simulated data and radar data.