Spectral interdependence of remote-sensing reflectance and its implications on the design of ocean color satellite sensors.
Spectral interdependence of remote-sensing reflectance and its implications on the design of ocean color satellite sensors.
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DOI：
10.1364/ao.53.003301
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发表时间：
2014-05
期刊：
影响因子：
1.9
通讯作者：
Z. Lee;S. Shang;Chuanmin Hu;G. Zibordi
中科院分区：
文献类型：
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作者：
Z. Lee;S. Shang;Chuanmin Hu;G. Zibordi
使用901个遥感反射光谱（R（rs）（λ），sr，λ从400到700 nm，分辨率为5 nm），我们评估了相邻光谱波段之间R（rs）（λ）的相关性，以表征（1）不同波段R（rs）（λ）的光谱依赖性和（2）高光谱R（rs）（λ）在多大程度上可以从多波段测量中重建。901 R（rs）光谱是在各种各样的水生环境中测量的，其中水的颜色从海洋蓝色到沿海绿色或棕色，叶绿素a浓度范围从~0.02到>100 mg m ³，底部深度从~1 m到>1000 m，底部基质包括沙子，珊瑚礁和海草。系统地计算了中心波长λ（k）和λ（l）处相邻谱带之间的相关系数R（Δλ）（λ（k），λ（l）），其中光谱间隙（Δλ=λ（l）-λ（k））分别在5，10，15，20，25和30 nm之间变化。结果表明，在所有的光谱带中，r（Δλ）随Δλ的增大而减小，但当Δλ≤20 nm时，r（Δ λ）仍大于0.97。此外，使用400和710 nm之间的15个光谱带，我们通过多元线性回归重建了高光谱R（rs）（λ）（从400到700 nm，分辨率为5 nm）。在400-700 nm范围内，每个波段的测量和重建R（rs）之间的百分比差异通常小于1%，相关系数接近1.0。对于每个波段，测量和重建的R（rs）之间的平均绝对误差约为0.00002 sr ³，这明显小于所有过去和当前海洋颜色卫星辐射测量产品的R（rs）不确定性。这些结果与早期研究的结果相呼应，即在可见光域中约15个光谱波段的R（rs）测量可以提供与高光谱（5 nm光谱分辨率的连续波段）测量几乎相同的光谱信息。这些结果为大容量高光谱数据的数据存储和处理以及未来海洋颜色卫星传感器的设计提供了见解。
Using 901 remote-sensing reflectance spectra (R(rs)(λ), sr⁻¹, λ from 400 to 700 nm with a 5 nm resolution), we evaluated the correlations of R(rs)(λ) between neighboring spectral bands in order to characterize (1) the spectral interdependence of R(rs)(λ) at different bands and (2) to what extent hyperspectral R(rs)(λ) can be reconstructed from multiband measurements. The 901 R(rs) spectra were measured over a wide variety of aquatic environments in which water color varied from oceanic blue to coastal green or brown, with chlorophyll-a concentrations ranging from ~0.02 to >100 mg m⁻³, bottom depths from ~1 m to >1000 m, and bottom substrates including sand, coral reef, and seagrass. The correlation coefficient of R(rs)(λ) between neighboring bands at center wavelengths λ(k) and λ(l), r(Δλ)(λ(k), λ(l)), was evaluated systematically, with the spectral gap (Δλ=λ(l)-λ(k)) changing between 5, 10, 15, 20, 25, and 30 nm, respectively. It was found that r(Δλ) decreased with increasing Δλ, but remained >0.97 for Δλ≤20 nm for all spectral bands. Further, using 15 spectral bands between 400 and 710 nm, we reconstructed, via multivariant linear regression, hyperspectral R(rs)(λ) (from 400 to 700 nm with a 5 nm resolution). The percentage difference between measured and reconstructed R(rs) for each band in the 400-700 nm range was generally less than 1%, with a correlation coefficient close to 1.0. The mean absolute error between measured and reconstructed R(rs) was about 0.00002 sr⁻¹ for each band, which is significantly smaller than the R(rs) uncertainties from all past and current ocean color satellite radiometric products. These results echo findings of earlier studies that R(rs) measurements at ~15 spectral bands in the visible domain can provide nearly identical spectral information as with hyperspectral (contiguous bands at 5 nm spectral resolution) measurements. Such results provide insights for data storage and handling of large volume hyperspectral data as well as for the design of future ocean color satellite sensors.