在MODIS中的光谱相关性 - - 脱水反射率检索不确定性
Optics express
|February 1, 2024
概括
这项研究引入了一种新方法来计算海洋颜色数据中的不确定性,提高了叶绿素a和光衰减估计的准确性. 考虑到光谱误差共变性,可以减少主要海洋产品的不确定性.
科学领域:
- 海洋学和远程传感技术
- 生物光学和生物地球化学海洋属性
背景情况:
- 光谱遥感反射率 (Rrs) 对于从卫星海洋颜色测量中得出水柱属性至关重要.
- 准确估计衍生地质产品的不确定性需要了解Rrs的不确定性及其光谱误差共变性.
研究的目的:
- 建立一种基于导数的方法,将不确定性传播到Rrs中,生成像素级错误共变率.
- 将这种方法应用于中等分辨率成像光谱辐射仪 (MODIS) 数据,并评估其对甲和分散衰减系数 (Kd{490)) 不确定性的影响.
主要方法:
- 开发了一种基于导数的方法,将仪器噪声,系统不确定性和前模型不确定性传播到Rrs.
- 将该方法应用于MODIS Aqua数据,使用多重散射Epsilon (MSEPS) 大气校正算法.
- 使用蒙特卡洛 (MC) 分析验证了方法,并使用现场Rrs.使用传播不确定性与观察到的差异进行了比较.
主要成果:
- 基于导数的方法成功地在Rrs.中生成了像素级错误共变量.
- 考虑到Rrs误差共变性,通常可以将甲基 (chl_a) 的估计相对不确定性降低1-10%,Kd{490) 的估计相对不确定性降低约2%,在特定地区的降低更大.
- 一个为期8天的全球复合研究表明,在深海水域上,可实现Cl_a的35%不确定性目标.
结论:
- 基于导数的方法提供了合理的Rrs误差共变率估计,提高了导数海洋学产品的准确性.
- 该方法有效地减少了叶绿素-a和Kd{490) 估计的不确定性,有助于更可靠的海洋颜色数据.
- 未来的改进工作应集中在改进关于带间误差相关性和校准和辅助数据不确定性的假设上.
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