基于水声方法的海面降雨动态监测技术研究

Rainfall data at sea plays an important role for carrying out the global atmospheric circulation and climate prediction. However, the rainfall measuring technology at sea is so extremely limited that there is very lack of rainfall data. Although the satellite remote sensing method is more effective to obtain the large-scale rainfall distribution, but lack of true value data validation from the measured data at sea surface. After all, for the uneven space-time distribution of the surface rainfall, rainfall measuring precision is more dependent on the time resolution. With a special phenomenon that rainfall at sea surface can produce sound underwater, a new method of rainfall monitoring at sea is put forward in this paper. It can make up the defects of satellite platforms technology in the temporal resolution. During the exploration process, the received sound data produced by rainfall at sea will cause distortion in different aquatic environment, and then affect the accuracy of the inversion method and applicable scope for rainfall at sea surface. This paper plan to explore the normalization method to obtain the sound source by studying internal mechanism of sound transmission in different aquatic environment. Then, through analysis of unique rainfall-sound features with different rainfall conditions at sea, rainfall intensity of quantitative problem can be solved and the rainfall dynamic monitoring technology will be realized based on underwater acoustic method.

海面降雨数据对开展全球大气环流和气候预报具有重要作用。然而目前浩瀚海洋上的降雨测量手段极其有限，数据十分缺乏。尽管卫星遥感是获得大尺度降雨分布的较有效方法，但对于空间分布极不均匀、时间尺度变化大的海面降雨来说，卫星监测结果缺乏足够的时间采样，并缺乏来自海面上的实测降雨真值数据的支撑。本文拟利用海面降雨会在水中辐射声音这一特珠现象，尝试建立一套基于水声方法的海面降雨动态监测技术，为海面降雨的监测提供一种新颖的方法，以弥补卫星监测结果的缺陷。然而在前期探索中发现，不同水体环境下获取的雨声由于存在传输畸变导致不能真实反映海面降雨声源特性，进而影响利用水声方法反演海面降雨的精度和适用范围。为此，本文拟通过研究雨声在不同水体环境中传输的内在机制，探索获取海面降雨声源特性的归一化方法，分析并完善不同降雨条件下独特的雨声特征，解决雨声与降雨强度的定量化问题，为最终实现海面降雨动态监测技术提供新方法。

本项目将降雨噪声作为一个海面噪声源，结合水声传播理论研究降雨噪声的规律，获了得降雨噪声随传播距离和深度的关系，可为降雨反演与监测提供技术支撑，同时，分析探讨了国内外各降雨反演公式存在的问题，为下一步开展雨声反演和基于海洋环境噪声的海面降雨动态监测技术奠定了基础。