Coupling the CUPID and TRGM Models to Study the Temporal Variations of Thermal Emission Directionality of Crop Canopies
Many field experiments have observed the significant temporal variation of TIR (Thermal Infrared) emission directionality, so it is necessary to quantitatively explain this phenomenon to improve the application of the directional remotely sensed TIR observation. In this paper, the 3D Thermal Radiosity Graphics Model (TRGM) and an extended energy balance model CUPID are coupled to simulate the seasonal and daily variation of directional brightness temperature (DBT) of wheat canopies. The improvement of CUPID model mainly focused on simultaneously retrieving the shaded temperature and sunlit temperature of soil surface, which is very important for coupling with TRGM Vegetation structure, soil water content and micrometeorology data are the main input parameters that affect the component temperature distribution. Driven by the input data set in situ, the half-hourly DBT dataset of wheat canopy are simulated for 22 days. Several new variables are defined to analyze the DBT temporal variation, which include nadir DBT, hot spot DBT, azimuthally averaged DBT at zenith angle of 55° standard deviation of DBT at zenith angle of 55° etc. The validation results show that the simulated directional temperature differences have consistent trend with field measurements. Based on the sensitivity analysis, it is found that the soil water content and air temperature are the two most significant factors that affect the DBT distributions, while the wind speed and solar radiation affect DBT much more than air temperature.
H.G.Huang Q.-H.Liu W.H.Qin
State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications,Chinese Acad State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications,Chinese Acad State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications,Chinese Acad
国际会议
Progress in Electromagnetics Research Symposium 2009(2009年电磁学研究新进展学术研讨会)(PIERS 2009)
北京
英文
1558-1562
2009-03-23（万方平台首次上网日期，不代表论文的发表时间）