Earthquake-related thermal-infrared abnormity detection with wavelet packet decomposition
利用小波包分析进行地震相关热红外辐射异常信息检测

Former researches show that thermal-infrared radiation abnormity can be observed before or after earthquakes.The thermal-infrared radiation of earth surface is composed of many elements,and the earthquake-related information is a weak signal in the strong background noise.So it is very difficult to extract it with a simple method mentioned by some researchers.We deal with this kind of earthquake-related information as a paroxysmal signal.The wavelet packet decomposition was used to analyze the time series of thermal-infrared radiation,the complicated elements were decomposed to different frequency band signals,According to the variation of the energy of these signals,the paroxysmal signal were detected.Results from Jiujiang earthquake on 26th,Nov.2005,Kamchatka Peninsula earthquake on 21st,Apr.2006,and Jiashi earthquake on 27th,Aug.1998,show that it is an effective approach to detect earthquake-related paroxysmal signal,but it is a key problem to understand the mechanism and temporal-spatial relationship between thermal-infrared abnormity signal and earthquake event.