基于Scholte波频散特性的测距方法研究

Studies on Ranging Method Based on Scholte Wave Dispersion Characteristic

针对具有弹性海底环境中水中低频宽带脉冲信号,研究基于Scholte波频散特性的被动测距方法。以简正波理论为基础,将海底地震波拾振器接收的时域信号表示成Scholte波与简正波之和,采用时频分析方法提取Scholte波与简正波到达时间,分别利用Scholte波不同频率处到达时间差以及Scholte波、简正波同频率到达时间差进行声源距离估计。对具有弹性海底的Pekeris波导环境中的脉冲声源进行仿真分析,结果表明,利用Scholte波不同频率处到达时间差以及Scholte波、简正波同频率到达时间差均可以有效进行声源距离估计,两种方法的距离估计结果不同,但测距误差均小于2%。

A passive ranging method based on the dispersion characteristics of Scholte wave is studied for low frequency wideband pulse signals in the Pekeris waveguide with elastic sea floor. Based on normal mode theory, the signal received on an ocean-bottom seismometer can be expressed as the sum of Scholte wave and normal modes. The arrival time of Scholte wave and normal modes can be extracted by time-frequency anaylsis, and then, the source range can be estimated by two methods. One is using the arrival time difference of Scholte at different frequencies, the other is using the arrival time difference of Scholte wave and normal modes at the same frequency. Simulation results from a shallow-water Pekeris waveguide with elastic sea floor show that the proposed two methods both can be used to estimate the range of source. The range estimation results of the two methods are dirrerent, and the relative errors in range estimation of the two methods are less than 2%.