| At present,the thermal IR remote sensing assisted methods for monitoring soil moisture content mainly includes thermal infrared method,thermal inertia method and temperature/vegetation index method.Among them,the thermal infrared method is relatively simple and easy to use,and is possible to retrieve soil moisture content from the data of ground temperature at daytime and especially in the condition of lacking the data of temperature range between day and night.Nevertheless,because the effect of soil moisture condition on soil temperature is considered only at a given time period,the accuracy of retrieval for soil moisture content by this method is usually not so ideal.The thermal inertia method has some advantages,such as clear physical meaning,higher accuracy in estimating soil moisture condition and also simple and easy to use.However,it also has some limitation.For example,this method can be used only in the regions with no or little vegetation cover and,in addition,the satellite data suitable used in this method are rather difficult to obtain timely.As to the temperature/vegetation index method,it also has clear physical meaning and can be used in many conditions.However,its calculation process is quite complicated and the data of some parameters used in the calculation are difficult to collect.In future,with the improvement of remote sensors and comprehensively application of different techniques,especially the combined use of thermal infrared technique and microwave one,the monitoring accuracy of soil moisture content with remote sensing will be greatly improved. |