Study of the microwave emissivity characteristics over Gobi Desert

35th International Symposium on Remote Sensing of Environment

地球科学;生态环境科学

Yubao, Qiu^1,2 ; Lijuan, Shi^1,2,3 ; Wenbo, Wu^3

Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China^1

Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, China^2

School of Geomatics, Liaoning Technical University, Fuxin, China^3

关键词: Different frequency;    Geographical environment;    Geophysical process;    Higher frequencies;    Microwave emissivity;    Negative correlation;    Polarization difference;    Surface energy budget;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/17/1/012249/pdf
DOI  :  10.1088/1755-1315/17/1/012249

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The microwave emissivity represents the capacity of the thermal radiation of the surface, and it is the significant parameter for understanding the geophysical processes such as surface energy budget and surface radiation. Different land covers have different emissivity properties, and the Gobi Desert in Central Asia seriously impact the sandstorms occur and develop in China, because of its special geographical environment and surface soil characteristics. In this study half-month averaged microwave emissivity from March 2003 to February 2004 over the Gobi Desert has been estimated. Emissivities in this area at different frequencies, polarization and their seasonal variations are discussed respectively. The results showed that emissivity polarization difference decrease as the frequency increases, and the polarization difference is large (0.03-0.127). The H polarization emissivity increases with increasing frequency, but the V-polarized microwave emissivity is reduced with increasing frequency because of the body scattering. In winter, emissivity decreases sharply in snow covered area, especially for higher frequencies (such as 89GHz). In addition, we compared emissivity with MODIS NDVI data at the same time in the Gobi Desert, and the results indicate that NDVI derived the good negative correlation with microwave emissivity polarization difference at 37GHz.