基于多普勒频移的水下运动目标测距技术

研究了基于多普勒频移的水下运动目标测距的方法及关键技术，采用了基于Hilbert变换的信号平稳化方法，结合频率匹配和PMTM多锥度法功率谱估计改善处理增益并提高线谱的短时频率估计精度，并结合几何模型及频率导数求解目标斜距。对算法进行了仿真，仿真结果表明，算法正确可行，在谱级信噪比不低于10dB条件下能有效提高被动式水下运动目标测距的精度。最后给出一个应用实例。

Passive ranging of underwater motional targets based on Doppler frequency shift

A method and key technology for passive ranging of underwater motional targets based on doppler frequency shift are studied in this paper. A method of signal balancing based on Hilbert transform is taken. The frequency matching method and PMTM method are used to improve the estimating precision of instantaneous frequency. Based on the geometrical model and the freqyency＇s differential coefficient, the target＇s bevel distance is calculated. The results of simulating experiments show that the arithmetic is correct and feasible, and can improve the passive ranging precision of underwater motional targets under condition of SNR higher than 10dB. In the end , an applied example based on this arithmetic is given.