摘要
利用2016年秋季现场观测数据,开展了东印度洋南部海域水体遥感反射率光谱特征研究,分析了不同方法(剖面法、水面之上法)测量结果之间的差异,以及两种水面之上数据处理方法结果的差异。研究发现:(1)东印度洋南部海域的遥感反射率随波长单调下降,具备清洁大洋水体的典型光谱特征,在光谱形状和量值等方面均与研究区历史观测数据具有较好的一致性;(2)与剖面法得到的遥感反射率光谱相比,水面之上法的测量结果总体偏大,二者的相对偏差在离水辐射较强的蓝光波段(412~490 nm)为15%~25%,在离水辐射较弱的绿光波段(555 nm)为47%~61%;(3)不同的水面之上数据处理方法引起的遥感反射率相对偏差在蓝光波段是4%~7%,在绿光波段是11%。分析了不同测量方法、数据处理方法所得结果存在差异的原因。
The spectral characteristics of the remote-sensing reflectance Rrs(λ) in the eastern Indian Ocean were analyzed based on in-situ optical measurement in autumn 2016. The Rrs(λ) measured by the two methods were compared, including the profiling method and above-water method. The above-water Rrs(λ) derived from two different kinds of data processing procedures were also compared in this paper. The research finds that:(1) The Rrs(λ) in the eastern Indian Ocean decreases monotonically towards longer wave length, exhibiting typical characteristics of the open clean ocean water. Besides, good agreement was found between our measurements and historical measured data.(2) The Rrs(λ) derived from above-water method are generally higher than that by the profiling method, with the median absolute percentage difference(MAPD) of 15%~25%(47%~61%) in the blue band(green band).(3)The MAPD of the Rrs(λ) derived from two different kinds of above-water data processing procedures is 4%~7%(11%)in the blue band(green band). The mechanism of the observed difference is analyzed with different measuring methods and data processing methods.
引文
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