The sound velocity inversion by EEOF coast acoustical tomography

In order to realize the real-time continuous monitoring of sound speed along coastal waters, a Double-transcever Coast Acoustical Tomography (DCAT) system is proposed in this paper. The main purpose to do so is to solve the problem on the insufficiency of acoustic ray inversion and the instability of receiving signal in the existing single-transcever coastal acoustic tomography system. The results obtained by computer simulation show that the sound speed inversion precision of DCAT system can be improved by one order of magnitude, which verifies the effectiveness of the system. In the process of sound speed inversion, the Extended Empirical Orthogonal Function (EEOF) is used to represent the sound speed profile and to realize the sound speed inversion of the whole water depth of the section. The DCAT system and EEOF method provide a theoretical basis and an effective way for the establishment and data processing of the real-time continuous observation system.