Comparison Of Brightness Temperature Images From Satellite Remote Sensing Of Infrared And Microwave And The Preliminary Application To Earthquake Monitoring

Remote sensing technology has been widely applied to earthquake research. Inparticular the thermal infrared remote sensing (TIR), has been used to detect seismicthermal in the early1990s. Compared to the traditional ground station networkobservation, the thermal infrared remote sensing has the advantages of high accuracy,wide coverage and quasi-real-time data acquisition. Thermal infrared remote sensingcan be used to detect infrared radiation anomalies caused by seismic activities andwhich has a broad application propect. But In the practical applications thetemperature products of the thermal infrared remote sensing are influenced by clouds.So it has some limitations. Passive microwave remote sensing could obtain thesurface radiation clearly, because it has the abilities to penetrating clouds and dust aswell as has less interfered by the atmosphere. So it can provid added for thermalinfrared remote sensing.In this thesis, I select the Sichuan-Yunnan earthquake key monitoring region asthe experimental area and research the Wenchuan earthquake using infrared andmicrowave remote sensing data. Firstly, the normal infrared and microwavebackground is established which uses statistical methods and then the abnormalinformation of infrared and microwave brightness temperature before the earthquakeare extracted using the model of brightness temperature offset index based on samecalendar year (K value method) and analysis their evolution process. At last, bycomparison of the different features of infrared and microwave remote sensing, andconsidering the impact of topography to them, we correct microwave brightnesstemperature to the infrared brightness temperature of the high resolution ratio. As aresult, two data source of brightness temperature are supplied for earthquakemonitoring and prediction.The conclusions of this thesis are described below：(1) Infrared and microwavebrightness temperature background field has similar characteristics of spatialcorrelation, temporal continuity and annual variation periods. The background is highin summer and low in winner, respectively, which is in accordance with the seasonal variation trend. In addition, the background is mainly controlled by landform andactive faults in spatial. In details, brightness temperature and elevation present anegative correlation. In one case over1000km, the lapse rate of infrared brightnesstemperature is0.48K in June while the lapse rate of microwave is0.31K.（2）In thecase study of the Wenchuan earthquake, the result illustrates that both infrared andmicrowave brightness temperature shows distinct anomaly before the earthquake, theformer appeared before41days before the event and the latter44days before,respectively. Both of the variations present a weak-strong-weak process.（3）It isfound that the infrared brightness temperature is higher than the microwave brightnesstemperature in plains, hills and mountains, but the D-value of them is different. It isthat the D-value in plain is highest, and in hill it is higher than that in mountain duringsummer while lower during winter. The difference of D-value of brightnesstemperature is caused by the topography and surface roughness, andthe the major cause is topography.（4）This study reveal that a quantitativerelationship exists between infrared and microwave brightness temperature and theoffset of them is related to topography. The monthly mean of infrared and microwavebrightness temperature in different topographical areas has been fitted by a linearequation, and the correlation coefficient of it is more than0.95which is very high. Asto the infrared brightness temperature, the residual error between the calculated valuesby linear equation and the observation value is very low. The result shows that theresidual is below1K during7months in plains, during5months in hills and during8months in mountains, respectively. Therefore, if the infrared brightness temperaturecould not been obtained when the interference factor is not avoided, the infraredbrightness temperature can be fitted based on microwave brightness temperature bythe linear equation.