SMOS与Aquarius卫星海表盐度测量方法及数据的对比分析

Comparison and Analysis of Sea Surface Salinity Measurement Method and Data Between SMOS and Aquarius

国际上发射的海表盐度遥感卫星主要有2颗:欧洲的SMOS和美国的Aquarius卫星,为给后续海表盐度遥感提供参考借鉴,对比分析了这2颗卫星的遥感器载荷、数据处理算法和盐度数据。遥感器载荷方面,SMOS采用L波段二维综合孔径辐射计,而Aquarius采用L波段实孔径辐射计加散射计;数据处理算法方面,分析了二者在介电常数模型、海面粗糙度校正以及反演算法方面的差异;盐度数据方面,分析了SMOS与Aquarius盐度数据之间的相关程度,并分别与ISAS(In Situ Analysis System)浮标盐度数据作对比,分析了2颗卫星的盐度数据精度。将2颗卫星的盐度遥感数据与ISAS浮标盐度数据对比发现,在全球范围内,Aquarius盐度测量精度优于SMOS;但在开阔海域,SMOS盐度测量精度优于Aquarius;而在近海岸区域,均出现较大的误差,且SMOS数据误差更大。

There are two main satellites for remote sensing of sea surface salinity(SSS)launched in the world:the SMOS from Europe and the Aquarius from the United States.In order to provide references for subsequent remote sensing of sea surface salinity,the two satellites are compared in three aspects:payload,data processing algorithm and salinity data.For payload,SMOS uses a L-band two-dimensional radiometer,while Aquarius uses a L-band real aperture radiometer and a scatterometer;for data processing algorithms,the differences between two satellites in dielectric constant models,sea surface roughness correction and retrieval algorithms are analyzed;for salinity data,the correlation between SMOS and Aquarius in salinity data is analyzed,and compared with ISAS buoy salinity data respectively,the accuracy of salinity data of two satellites is analyzed.By comparison,it is found that the salinity data accuracy of Aquarius is better than that of SMOS from global perspective.However,in the open sea area,the salinity data accuracy of SMOS is better than that of Aquarius;in the offshore area,there are relatively big errors for the salinity data of both satellites,and the error is even bigger in the salinity data of SMOS.