【摘要】 欲从热红外辐射中找到构造活动与地震活动的信息 ,需要考虑 2个基本问题 ,即大气的影响和地表热红外辐射的稳定场。通过以下方面的工作尝试对上述问题进行了研究 :1 )提出了地表亮度温度及年变基准场的概念。 2 )利用NOAA卫星 2 0年的观测资料 ,文中在获得地表亮温 (LSBT)的基础上 ,借用分离窗方法和小波分析方法 ,提取了中国地表亮温的年变基准场 ,为进一步分析异常场打下了基础。计算表明 ,大气的影响一般在± 1 0K范围内。更多还原

【Abstract】 For extracting the information about fault activity and seismicity from thermal infrared radiation, two crucial problems should be taken into consideration: 1) Aerosphere exists between solid earth and the satellite based sensor, and thus influences the infrared energy of land radiation when it passes through the aerosphere to arrive at the sensors. Moreover, the atmosphere itself is involved in thermal radiation, too. Therefore, to extract the geophysical information from thermal radiation, we have to begin with the estimation of atmospheric influence; 2) for identifying the anomalies induced by fault activity in thermal radiation, we should be able to distinguish the normal radiation from anomalous radiation, as anomaly can only be identified in reference with normality. This paper discusses these problems from the following aspects: 1) define the concepts of land surface brightness temperature (LSBT) and its annual variation field. LSBT would be an important physical concept in extracting the geophysical information from thermal radiation. LSBT should be assigned to the category of radiation energy of land surface, rather than the traditional "temperature" concept. Once the emissivity is known, the temperature can easily be calculated according to Planck law; 2) introduce the split window method for calculating the LSBT and the influence of atmosphere. The calculation shows that the influence of atmosphere on brightness temperature received by satellite based sensor is about ±10K; 3) the annual variation field of LSBT in China is extracted from the LSBT data by using the wavelet and split window methods; the data used in this study come from the observations of NOAA/AVHRR from 1981 to 2001. The results of this study may provide a basis for further analyzing the anomaly field of thermal radiation.更多还原