摘要
A surface soil moisture model with improved spatial resolution was developed using remotely sensed apparent thermal inertia（ATI）.The model integrates the surface temperature derived from TM/ETM＋ image and the mean surface temperature from MODIS images to improve the spatial resolution of soil temperature difference based on the heat conduction equation,which is necessary to calculate the ATI.Consequently,the spatial resolution of ATI and SMC can be enhanced from 1 km to 120 m（TM） or 60m（ETM＋）.Moreover,the enhanced ATI has a much stronger correlation coefficient（R^2） with SMC（0.789） than the surface reflectance（0.108） or the ATI derived only from MODIS images（0.264）.Based on the regression statistics of the field SMC measurement and enhanced ATI,a linear regression model with an RMS error of 1.90%was found.
基于热传导理论建立土壤日温差模型,可实现基于TM影像提取特定深度的土壤日温差信息。利用该模型获取的土壤日温差与ATI的分辨率可达到120 m(TM)或60 m(ETM+)。荒漠矿区实验表明,实测土壤水分与MODIS得到的ATI的相关系数仅为0.264,而与改进模型得的高分辨率ATI相关系数为0.789,监测的土壤水分均方根误差为1.90%(m3/m3)。提出的方法同样还适用于其他具有热红外波段的高分辨率影像结合ATI的土壤水分提取。
基金
Project (2013CB227904) supported by the National Basic Research Program of China
Project (2012QNB09) supported by the Fundamental Research Funds for the Central University,China
Project (NCET-12-0956) supported by the Program for New Century Excellent Talents
