基于多频被动微波遥感的土壤水分反演——以黑河上游为例  

Retrieval of Soil Moisture based on Multi-frequency Microwave Remote Sensing:Study of HiWATER

作　　者：王舒[1] 蒋玲梅 王健 Wang Shu;Jiang Lingmei;Wang Jian(National Meteorological Information Center,Beijing 100081,China;State Key Laboratory of Remote Sensing Science,Jointly Sponsored by Beijing Normal University and Aerospace Information Research Institute of Chinese Academy of Sciences,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China)

机构地区：[1]国家气象信息中心,北京100081 [2]北京师范大学/中国科学院遥感与数字地球研究所遥感科学国家重点实验室,北京师范大学地理科学学部,北京100875

出　　处：《遥感技术与应用》2020年第6期1414-1425,共12页Remote Sensing Technology and Application

基　　金：国家自然科学基金青年科学基金项目(41701411)。

摘　　要：土壤水分是陆地生态系统中最重要的组成部分,如何有效地得到高精度的土壤水分产品成为当前研究最为关注的问题。被动微波遥感具有监测面积大、重访周期短、对土壤水分敏感等优点,成为反演土壤水分最有潜力的方式。基于SMOS(Soil Moisture and Ocean Salinity)和AMSR2(The Advanced Microwave Scanning Radiometer-2)数据,通过研究L波段与C波段融合亮度温度在土壤水分反演中的潜力,发展多频率土壤水分反演算法,并对黑河上游4个像元开展土壤水分反演研究。结果表明:①利用L/C组合亮温反演结果与实测数据较为吻合,长时间内变化趋势一致,相关系数为0.841,均方根误差为0.063 m^3/m^3。②通过与SMOS和AMSR2官方土壤水分产品比较发现,AMSR2土壤水分产品存在明显的低估,SMOS土壤水分产品缺失值较多,无法得到较为完整的土壤水分时间序列;利用L/C多频率组合反演得到的结果明显优于官方土壤水分产品。融合L与C波段亮温数据,可有效提高反演土壤水分精度,实现高精度土壤水分的获取。Soil moisture in the Earth system plays a vital role in the global energy balance.Therefore,how to effectively obtain the high spatio-temporal resolution of soil moisture becomes an important research problem.The passive microwave remote sensing technique,which has a large spatial coverage,high temporal resolution and is sensitive to surface water content,has been shown to be an efficient approach for large scale soil moisture monitoring.Based on the characteristics of SMOS and AMSR2 data,and the multi-frequency soil moisture inversion algorithm by combining L-band and C-band brightness temperature,and 4 pixel of the upper of the Heihe River were used for soil moisture retrieval.The better results showed when using combination of L/C multifrequency,the correlation coefficient was 0.841,and the root mean square error was 0.063.Compared with the official soil moisture products of SMOS and AMSR2,it is found that the AMSR2 soil moisture product is obviously underestimated,and the SMOS soil moisture product has many missing values,which cannot accurately reflect the soil moisture in the study area.The results obtained by L and C multi-frequency algorithm inversion are significantly better than the official soil moisture products.Combined the L-band and C-band Tb can achieve higher accuracy of soil moisture.

关 键 词：土壤水分 AMSR2 SMOS 黑河上游 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]