多源遥感协同下的全天候地表温度反演方法

The integration of passive microwave (MW) remote sensing and thermal infrared (TIR) remote sensing is a practical and feasible way to retrieve all-weather land surface temperature (LST). However, due to scientific problems in the related theories and methods, the integration is still limited. With the entry point, the inconsistence of physical meaning and spatial resolution between MW LST and TIR LST, this project focuses on the correction of thermal sampling depth, the retrieval of MW LST, the determination of temporal component of LST and the generation and evaluation of all-weather LST. The content of this project consists of the following four sections: (1) Addressing thermal sampling depth correction, a model will be developed to convert the LST to MW effective temperature. The model will be supposed to make the MW LST physically consistent with the TIR LST. (2) The method retrieving the MW LST will be coupled with the model developed in section (1) to improve the accuracy of the estimated MW LST. (3) Based on the temporal component decomposition of LST, the steady-state and unsteady-state component of LST will be determined from the TIR LST time series and MW LST time series. (4) The generated all-weather LST with moderate spatial resolution will be intercompared and validated to ensure its applicability. Aiming at making a break through the difficulties in the theories and developing new methods related with the all-weather LST, this project will be beneficial to enhance the ability of remotely sensed LST when applied in the hydrology, environment and ecology.

被动微波与热红外遥感协同互补，是反演全天候地表温度的可行途径，但目前其理论方法均存在瓶颈和难题。本项目以被动微波与热红外地表温度“物理意义不一致”和“空间分辨率不一致”为切入点，以“热采样深度纠正—被动微波地表温度反演—时间尺度分量确定—全天候地表温度生成与检验”为主线，开展以下研究：1）发展面向被动微波等效温度-地表温度转换的热采样深度纠正模型，从理论上解决被动微波与热红外地表温度物理意义不一致的难题；2）实现热采样深度纠正模型与被动微波地表温度反演算法的耦合，显著提高被动微波遥感反演的地表温度的精度；3）基于时间尺度模型，发挥热红外时序观测和被动微波全天候观测的优势，确定地表温度的稳态和非稳态分量；4）对生成的中分辨率逐日地表温度开展交叉检验、直接检验和图像质量评价，确保其精度。本项目力求在理论难题上有所突破，在方法上有创新发展，以期增强遥感地表温度在水文、环境和生态等领域的应用能力。

被动微波与热红外遥感协同互补，是反演全天候地表温度的可行途径，但目前其理论方法均存在瓶颈和难题。本项目以被动微波与热红外地表温度“物理意义不一致”和“空间分辨率不一致”为切入点，以“热采样深度纠正—被动微波地表温度反演—时间尺度分量确定—全天候地表温度生成与检验”为主线，开展了以下科学探索与研究：1）探究了被动微波热采样深度对地表温度反演的作用机理，探究了热采样深度影响对地表覆盖类型、植被、土壤等参数的依赖，建立了相应的纠正模型；2）耦合热采样深度纠正模型，从被动微波遥感遥感数据实现地表温度反演，改善了被动微波遥感与热红外遥感地表温度的物理意义不一致，提高了反演精度；3）基于时间尺度模型，在时空双维度上对卫星热红外和被动微波遥感地表温度进行集成，实现了两种遥感手段的优势互补，形成了基于极轨卫星遥感反演全天候地表温度的有效方法；4）基于地面站点实测数据和高质量卫星热红外遥感地表温度产品，对所建立方法的反演结果进行了直接检验和交叉检验，并评价了图像质量。经过4年研究，本项目在全天候地表温度反演的理论与方法方面取得了创新与突破，并通过科学数据集研制和共享，增强了遥感地表温度在多个领域的应用能力。.在本项目的支持下，一共出版专著2部、发表期刊论文16篇，其中SCI期刊论文15篇，发明专利4项，其中2项获得授权；研制发布“中国陆域及周边逐日1km全天候地表温度数据集（TRIMS LST）”，产生了积极广泛的影响。