遥感反演地表温度的角度归一化方法研究

项目名称： 遥感反演地表温度的角度归一化方法研究

项目编号： No.41401375

项目类型： 青年科学基金项目

立项/批准年度： 2015

项目学科： 地理学

项目作者： 任华忠

作者单位： 北京大学

项目金额： 8万元

中文摘要： 准确获取地表温度信息是地表过程物质与能量交换、水热循环及其全球变化等研究的关键环节。由于像元组分温差与组分比例的影响，像元尺度地表温度往往表现出一定的方向性，从而在理论上降低了由不同方向观测数据反演的地表温度产品之间的可比性，严重限制了地表温度产品的实际应用。 本研究从地表温度角度效应这一关键问题出发，在分析现有地表温度遥感反演理论的基础上，把握组分温差与植被覆盖度对地表温度角度效应的主导因素，构建地表方向性热辐射的参数化模型，充分利用时空信息与光谱信息发展从双时相双通道热红外遥感数据进行地表温度角度归一化(即获取垂直方向上的地表温度)的物理模型，并实现物理模型的实际运用与验证。将最终形成一套操作性强、输入数据少的地表温度角度归一化技术体系，为未来业务化生产角度归一化后的地表温度产品提供技术支撑，以促进不同地表温度产品的可比性及其在各个领域的广泛应用。

中文关键词： 地表温度；角度归一化；方向性热辐射；方向性发射率；热红外遥感

英文摘要： Accurate acquisition of land surface temperature (LST) from remote sensing data is crucial for the researches such as earth’s material and energy exchanges, water and energy cycles, global changes and so on. Because of the differences of components’ temperatures and proportions at different viewing directions, the LST at pixel always presents an angular variation, which reduces the comparability of the LST products retrieved from remote sensing data observed at different directions and consequently limits the applications of LST in some relative domains. On the basis of the principle of LST retrieval methods from remote sensing data, this study aims at the angular normalization (i.e., to retrieve the LST at nadir direction) of LST by making full use of the spatio-temporal and spectral information included in the used data. With the considerations of two important factors, components’ temperature differences and fraction of vegetation cover that cause the angular variation of LST, this study will start with the modelling of the directional thermal radiation of land surface, and then develop a physics-based model to achieve angular normalization of LST by using two-channel thermal infrared data observed at two times (daytime and nighttime). With the above work, the study will finally establish an operational

英文关键词： Land surface tempearature；Angular Normalization；Directional thermal radiation；directional emissivity；thermal infrared remote sensing