Zhang Minwei, Tang Junwu, Dong Qing, Duan Hongtao, Shen Qian
Opt Express. 2014 Apr 7;22(7):7906-24. doi: 10.1364/OE.22.007906.
We have presented an atmospheric correction algorithm for HJ-1 CCD imagery over Lakes Taihu and Chaohu with highly turbid waters. The Rayleigh scattering radiance (Lr) is calculated using the hyperspectral Lr with a wavelength interval 1nm. The hyperspectral Lr is interpolated from Lr in the central wavelengths of MODIS bands, which are converted from the band response-averaged Lr calculated using the Rayleigh look up tables (LUTs) in SeaDAS6.1. The scattering radiance due to aerosol (La) is interpolated from La at MODIS band 869nm, which is derived from MODIS imagery using a shortwave infrared atmospheric correction scheme. The accuracy of the atmospheric correction algorithm is firstly evaluated by comparing the CCD measured remote sensing reflectance (Rrs) with MODIS measurements, which are validated by the in situ data. The CCD measured Rrs is further validated by the in situ data for a total of 30 observation stations within ± 1h time window of satellite overpass and field measurements. The validation shows the mean relative errors about 0.341, 0.259, 0.293 and 0.803 at blue, green, red and near infrared bands.
我们针对太湖和巢湖等水体浑浊度高的区域，提出了一种用于HJ-1 CCD影像的大气校正算法。利用波长间隔为1nm的高光谱瑞利散射辐射率（Lr）来计算瑞利散射辐射率。高光谱Lr是根据MODIS波段中心波长处的Lr进行插值得到的，而这些中心波长处的Lr是由使用SeaDAS6.1中的瑞利查找表（LUT）计算得到的波段响应平均Lr转换而来。气溶胶引起的散射辐射率（La）是根据MODIS波段869nm处的La进行插值得到的，该La是通过短波红外大气校正方案从MODIS影像中推导出来的。大气校正算法的精度首先通过将CCD测量的遥感反射率（Rrs）与MODIS测量值进行比较来评估，而MODIS测量值则通过现场数据进行验证。在卫星过境和实地测量的±1小时时间窗口内，对总共30个观测站的现场数据进一步验证了CCD测量的Rrs。验证结果表明，在蓝、绿、红和近红外波段，平均相对误差分别约为0.341、0.259、0.293和0.803。
