L波段土壤等效温度与热红外温度的差异分析及模型构建

MODEL BUILDING AND VARIANCE ANALYSIS BETWEEN SOIL EFFECTIVE TEMPERATURE OF L BAND AND SOIL THERMALINFRARED TEMPERATURE

利用河北怀来地区2006～2009年的气象观测数据驱动土壤水热耦合(SHAW)模型建立土壤温湿度廓线数据库,计算不同天气条件下逐时的L波段土壤等效温度,分析L波段土壤等效温度与热红外皮肤温度的差异。在Wigneron J P等提出的L波段等效温度计算模型的基础上,分析模型系数的时间效应,提出在土壤等效温度模型中通过引入土壤热红外温度时间序列数据信息以提高模型计算精度的有效方法。4a数据的平均计算精度由RMSE=2.40K提高到RMSE=0.81K,在土壤较干燥的情况下模型计算精度的改善更加明显。

A database including hourly soil temperature and moisture profiles was build up on the basis of Simulta- neous Heat and Water（SHAW） model driven by meteorological observation data span from 2006 to 2009 in Huailai test station, and synchronize soil effective temperature and moisture in L band was computed by using microwave radiative transfer model, the difference between soil effective temperature in L band and infrared surface tempera- ture was analyzed. Base on soil effective temperature model in L band presented by Wigneron et al, the time series data of soil infrared temperature were added into computing considering the time dependent effect of model coeffi- cients and accumulative effect of soil moisture, which evidently improved the computing precision. The average L band effective temperature RMSE of four years was decreased from 2.40K to 0.81K. Especially in try soil condi- tion, this enhancement is more significantly.