远程事件次声监测中的信号参数二维子空间计算方法  

Two-dimensional subspace algorithm for the slowness and azimuth of infrasound signals in the distant events monitoring

作　　者：孟亮 李夕海 刘代志 

机构地区：[1]火箭军工程大学,西安710025

出　　处：《地球物理学报》2017年第2期678-687,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41374154)资助

摘　　要：越来越多的观测发现,在地震、火山爆发、泥石流等重大自然灾害发生前,常产生异常的次声信号,这为地震及其他自然灾害的预报工作增加了一种可能的信息;同时,次声还是监测大气层、浅地表爆炸的有效手段.在自然灾害和爆炸事件次声监测中,慢度和方位角等参数对于源信号传播、定位以及源性质识别等工作具有重要意义.然而,目前的慢度和方位角等参数的算法——频率波数(FK)分析法,尚存在精度和分辨率不高等问题,特别是对多源次声信号的识别能力较差.为提高次声信号的监测精度,基于次声信号和噪声的子空间不相关性,构建了次声信号慢度和方位角二维子空间计算模型,并在此基础上提出了一种高分辨率次声信号二维子空间算法,仿真实验和实际数据的对比分析结果表明:本文提出的方法在精度和分辨率方面明显优于FK法,且能够更好地分离多源次声信号.More and more observations show that abnormal infrasonic signals are usually produced before the occurrence of earthquakes, volcanic eruptions, landslides and other natural disasters, which offers a possible method to forecast the earthquakes and other natural disasters. Besides, the infrasound monitoring is an effective method to monitor the atmosphere and shallow explosions. Both in the monitoring of natural disasters and explosions, the slowness and azimuth are very important for the infrasonic signal propagation, location and infrasonic sources recognition. The common method for calculating the slowness and azimuth is the Frequency Wavenumber （FK）, but when the FK method is applied to the infrasonic signal processing, the accuracy and resolution are not high, furthermore, this method canrt identify multiple infrasonic and then, a high-resolution calculation algorithm is proposed. The comparative analysis of the simulative and actual data shows that the proposed algorithm is significantly better than the FK method in terms of accuracy and resolution, and also can identify multiple infrasound signals effectively.

关 键 词：自然灾害 爆炸 次声信号 FK法 子空间 

分 类 号：P631[天文地球—地质矿产勘探]