【摘要】 Aquarius是NASA于2011年6月发射的基于主被动遥感技术的盐度观测卫星,其主要载荷是一个工作于L波段的微波辐射计。Aquarius天线三波束扫描刈幅可达390km,在7d内完成对全球海域的盐度观测。海面风浪导致海面粗糙度的变化,进而影响海面微波辐射特性。粗糙海面辐射亮温是盐度信息提取的重要误差源,需要发展相应的海面辐射模型进行修正。本文利用Aquarius观测的海表亮温数据,与扫描微波辐射计WindSat测量数据进行时空匹配,建立了一个描述粗糙海面L波段辐射特性的参数化模型,进而利用该模型进行了海表盐度反演,并将反演结果与Argo实测盐度数据进行了比较。结果表明,本文发天展的参数化模型可以准确描述中低风速条件下的粗糙海面辐射,在12m/s以上高风速条件下对粗糙海面亮温存在高估;采用此模型反演的盐度误差优于0.5,在高风速条件下盐度反演误差可超过1。更多还原

【Abstract】 Aquarius is a satellite which mission focuses on the measurement of sea surface salinity from space and was launched in June 2011 by NASA.The main payload of Aquarius is an L-band microwave radiometer.The swath width of three Aquarius beams is 390 km,which ensures the satellite can map the global oceans in a week.Meanwhile,the sea surface wind field and waves induce the extra roughness to oceans and affect the radiation characteristicsof rough sea surface.It is widely accepted that the brightness temperature from rough sea surface is a significant error sources for salinity remote sensing and a geophysical model function is essential to correct the roughness effect in the brightness temperature measured by space-borne radiometer.In this research,ageophysical model function for L-band rough sea surface radiation is developed based on the match-up data from Aquarius and WindSat.The GMF is involved in a sea surface salinity retrieval procedure and the results are validated with in-situ measurements from Argo buoy.It is indicated that the GMFaccurately depicts the emission properties of rough sea surface under low-moderate wind speed conditions and the standard deviation differences between Aquarius and Argo salinities are less than 0.5.The performance of the GMF degrades under high wind speed(>12 m/s),the standard deviation is more than 1.更多还原