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热红外遥感提供地表表层辐射信息为主,被动微波遥感可更好地提供植被和土壤背景垂直结构的辐射信息。结合热红外与被动微波遥感的优势协同反演植被和土壤组分温度是提高组分温度反演精度的一种思路。本文在对热红外辐射传输模型和微波辐射模型进行比较的基础上,构建均匀作物的统一场景,将统一场景的参数分为直接参数和间接参数。基于统一场景,修改微波辐射模型的场景结构及叶倾角分布,并增加组分温度参数以计算辐射亮温,最终构建热红外与微波辐射联合模拟模型(UEasmmes模型)。针对均匀玉米作物,利用UEasmmes模型进行联合模拟,分析了组分温度、组分发射率、叶面积指数LAI及叶倾角分布LAD对热红外与微波的方向性亮温DBT的敏感性响应差异。分析结果表明:协同热红外与被动微波遥感反演植被和土壤组分温度是可行的,但对于如何克服组分发射率、LAI及LAD对植被有效发射率的影响而导致的微波辐射亮温变化以及实现热红外表皮温度与微波等效温度之间的转化仍是需要深入研究和探讨的问题。
Thermal infrared remote sensing provides surface surface radiation information, and passive microwave remote sensing can better provide the radiation information of the vertical structure of vegetation and soil background. Combined with the advantages of thermal infrared and passive microwave remote sensing, the synergistic inversion of vegetation and soil component temperature is an idea to improve the accuracy of component temperature inversion. Based on the comparison of thermal infrared radiation transmission model and microwave radiation model, a unified scene of uniform crop is constructed, and the parameters of uniform scene are divided into direct parameters and indirect parameters. Based on a unified scenario, the scene structure and leaf tilt distribution of the microwave radiation model were modified, and the temperature parameters of the components were added to calculate the radiation bright temperature. Finally, a joint simulation model of thermal infrared and microwave radiation was established (UEasmmes model). Aiming at the uniform maize crop, the UEasmmes model was used to carry out the joint simulation. The differences in the sensitivity of DBT between thermal infrared and microwave were analyzed. The components temperature, component emissivity, leaf area index LAI and leaf inclination angle LAD were analyzed. The results show that it is feasible to reconstruct vegetation and soil component temperature by using thermal infrared and passive microwave remote sensing. However, how to overcome the effect of component emissivity, the effect of LAI and LAD on the effective emissivity of vegetation, And the conversion between thermal infrared skin temperature and microwave equivalent temperature still need further study and discussion.