中红外反射率遥感反演与新植被指数模型的建立

项目名称： 中红外反射率遥感反演与新植被指数模型的建立

项目编号： No.40801140

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 唐伯惠

作者单位： 中国科学院地理科学与资源研究所

项目金额： 19万元

中文摘要： 3～5um的中红外电磁波谱具有能够穿透大部分烟雾、阴霾，且受大气层中水汽影响很小等诸多优势，使得中红外遥感蕴藏着巨大的应用潜力。本项目针对中红外反射率反演存在的主要问题与不足，提出了利用MODIS数据两相邻中红外通道22（中心波长3.97um）和23（中心波长4.06um）白天过境地表亮温之间的差异来反演地表双向反射率，从而实现中红外反射辐射和地表自身热辐射的分离，进而开展野外观测实验，对中红外地表双向反射率的反演结果进行验证，结果表明反演误差在0.002之内。同时，根据反演的中红外地表双向反射率，提出了用中红外反射率替代红光反射率来建立一种新的植被指数模型，结果表明建立的新植被指数模型能比NDVI更好地描述地表的植被覆盖信息。此外，本项目还提出了中红外地表方向发射率的遥感估算方法和宽波段地表发射率的遥感估算方法。共发表科技论文4篇，其中SCI论文2篇，EI论文1篇。本项目所取得的研究成果将为中红外地表温度的遥感反演奠定了很好的基础，为开拓应用中红外波谱在其他方面的应用提供技术支持，对研究地表能量平衡和全球气候变化等研究具有重要意义。

中文关键词： 中红外；双向反射率；植被指数；发射率；MODIS

英文摘要： The mid-infrared (MIR) spectral region (3～5um) is of increasing interest with respect to current Earth observations, and has many advantages for various applications. Focused on the principal issues and shortcoming in the current remote sensing research of retrieving bi-directional reflectivity from mid-infrared, this project proposed to estimate the land surface bi-directional reflectivity in the MIR from MODIS channels 22 (wavelength centred at 3.97 um) and 23 (wavelength centred at 4.06 um), based on the difference in ground brightness temperature in these two MIR channels. In addition, to test the accuracy of the proposed model, field experiment observations had been carried out to valide the retrieved land surface bi-directional reflectivity. The results showed that the proposed model is acceptable with retrieved error within 0.002. Furthermore, a new vegetation index (VI) model has been constructed with surface bi-directional reflectivity in MODIS NIR and MIR channels. Compared with NDVI, the VI can better describe the land cover state of vegetation. In addition, the estimation of land surface directional emissivity in MIR and the estimation of broadband surface emissivity have also been proposed in this project. Totally, 4 scientific papers including 2 SCI and 1 EI cited papers have been published in the open scientific literatures. The results achieved in this project will be very helpful to retrieve land surface temperature from MIR, and also provides technical surpports for the other applications of MIR remote sensing, which will be very significant for the researchs such as the surface energy balance and the global climate change.

英文关键词： mid-infrared; bi-directional reflectivity; vegetation index; emissivity; MODIS