用信号处理技术及传播理论还原雷声频谱

Thunder acoustic spectrum obtained by using digital signal processing and propagation effects

以往关于雷声的研究都限于观测点雷声频域范围的探讨,由于噪音和衰减因素的影响,观测点的雷声频谱有很大失真.针对在兰州地区观测的一次雷暴过程中的雷声信号,利用数字信号处理技术,由观测点处的雷声音频信号得到频率谱,并对雷声频谱进行噪音分析;然后结合声音在大气中传播的衰减理论,分析了不同大气环境对声吸收的影响,并推算出了声源附近的雷声频率谱.

There are a few references on thunder at present, moreover they are all about thunder frequency spectrum at observation location. However, thunder frequency spectrum in observation location is a distorted signal because of noises and sound attenuation effects. In this paper, thunder signal from lightning discharge channels is obtained in Lanzhou of China. By using digital filter and Fourier transform, thunder frequency spectrum at the observation location is gained. Then, thunder frequency spectrum near lightning discharge channel is computed with the theory of sound propagation effects.