基于简正波掠射角的声速剖面反演方法研究

针对浅海宽带信号多途的特点,对多途分离的方法进行了研究,提出了一种基于warping变换的简正波分离和简正波信息提取的方法.随后提出了一种基于射线-简正波理论的利用各阶简正波中不同频点信号到达掠射角进行声速剖面反演的方法,最后通过仿真计算验证本方法可以应用于具有一定时间长度的线性调频发射信号的简正波分离,分离后提取的简正波信号经逆运算还原后与原始信号基本一致,分别对每阶简正波的各个频点到达掠射角进行计算,利用各阶简正波的不同频点到达掠射角建立代价函数,进行声速剖面反演.仿真结果证实了该方法的可行性,并分析了反演精度.

Inversion of the sound speed profile based on the grazing angle of normal modes

For the research on the multipath characteristics of shallow- water wideband signals,the methods of multipath separation were explored. A new method of multipath separation for shallow- water wideband acoustic signals based on warping transformation was proposed,and an inversion method of the sound speed profile in the local seas was proposed based on the grazing angle of the normal modes. Finally,the simulation validation of the method proved to be applicable to normal modes with the length of time in transmitted chirp signal separation,the separation and extraction of the normal- mode signal by the inverse operation after the reduction was consistent with the original signal,respectively for each order of the normal modes and each frequency point to reach the grazing angles through calculation by using different frequencies for each normal mode to establish the cost function while reaching the grazing angle and the inversion of the sound speed profile. Simulation results have verified the feasibility of the method,and the retrieval accuracy has been analyzed.