Eplee R E, Robinson W D, Bailey S W, Clark D K, Werdell P J, Wang M, Barnes R A, McClain C R
Science Applications International Corporation, Beltsville, Maryland 20705, USA.
Appl Opt. 2001 Dec 20;40(36):6701-18. doi: 10.1364/ao.40.006701.
We present an overview of the vicarious calibration of the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS). This program has three components: the calibration of the near-infrared bands so that the atmospheric correction algorithm retrieves the optical properties of maritime aerosols in the open ocean; the calibration of the visible bands against in-water measurements from the Marine Optical Buoy (MOBY); and a calibration-verification program that uses comparisons between SeaWiFS retrievals and globally distributed in situ measurements of water-leaving radiances. This paper describes the procedures as implemented for the third reprocessing of the SeaWiFS global mission data set. The uncertainty in the near-infrared vicarious gain is 0.9%. The uncertainties in the visible-band vicarious gains are 0.3%, corresponding to uncertainties in the water-leaving radiances of approximately 3%. The means of the SeaWiFS/in situ matchup ratios for water-leaving radiances are typically within 5% of unity in Case 1 waters, while chlorophyll a ratios are within 1% of unity. SeaWiFS is the first ocean-color mission to use an extensive and ongoing prelaunch and postlaunch calibration program, and the matchup results demonstrate the benefits of a comprehensive approach.
我们概述了宽视场海洋观测传感器（SeaWiFS）的替代校准。该计划有三个组成部分：近红外波段的校准，以便大气校正算法能够反演开阔海洋中海洋气溶胶的光学特性；可见光波段相对于海洋光学浮标（MOBY）水下测量值的校准；以及一个校准验证计划，该计划利用SeaWiFS反演结果与全球分布的水表面辐射率现场测量值之间的比较。本文描述了为SeaWiFS全球任务数据集第三次重新处理所实施的程序。近红外替代增益的不确定性为0.9%。可见光波段替代增益的不确定性为0.3%，对应水表面辐射率的不确定性约为3%。在一类水体中，SeaWiFS水表面辐射率与现场测量值的匹配比平均值通常在单位值的5%以内，而叶绿素a比值在单位值的1%以内。SeaWiFS是首个使用广泛且持续的发射前和发射后校准计划的海洋颜色观测任务，匹配结果证明了综合方法的益处。
