基于改进非线性劈窗算法的VIIRS中红外海面耀斑区反射率计算

发布时间：2018-05-15 09:24

本文选题：中红外 + 太阳耀斑区　；参考：《光谱学与光谱分析》2017年02期

【摘要】：传感器入瞳处接收到的中红外波段(3~5μm)能量包含反射的太阳能量与地物自身的发射能量。通常该波段反射的太阳能量很弱,但在海面太阳耀斑区等特定情况下,被中红外通道探测到的反射太阳能量是比较可观的,且其对大气影响的敏感性较低,同时,对于搭载有在轨定标系统的卫星传感器,使用黑体定标后的中红外波段的在轨辐射性能相当稳定的。因此,考虑将中红外波段的海面耀斑区反射率作为用于反射太阳波段交叉定标的基准。基于这个想法,构建了改进的、适用于VIIRS(visible infrared imaging radiometer)中红外波段的非线性劈窗模型来计算南印度洋海面耀斑区中红外反射率。首先统计得到VIIRS M12和M13波段海面反射率的限定关系,然后使用非线性劈窗算法模拟计算海面反射率,模拟模型的不确定度为0.83%。在此基础上使用VIIRS的M12波段(中心波长为3.697μm)太阳耀斑区数据计算选取的样本区的海面反射率。然后使用两种方法对反射率精度进行验证,精度分别为0.29%和0.23%,假设M12和M13波段海面反射率相等的反射率计算结果精度分别为2.48%和1.03%。该计算模型大大提高了精度,说明该模型用于VIIRS M12中红外波段计算海洋耀斑区反射率是有效可行的,其精度能够满足中红外波段海面反射率作为波段间定标基准的需求。
[Abstract]:The medium infrared band (3 ~ 5 渭 m) energy received by the sensor in the pupil contains the reflected solar energy and the emission energy of the ground object itself. Usually, the reflected solar energy in this band is very weak, but under certain conditions such as solar flares on the sea surface, the reflected solar energy detected by the mid-infrared channel is considerable, and its sensitivity to the atmospheric influence is low, at the same time, For satellite sensors with on-orbit calibration system, the in-orbit radiation performance of mid-infrared band after blackbody calibration is quite stable. Therefore, the reflectivity of the sea flare region in the mid-infrared band is considered as the reference for cross-calibration of the reflected solar band. Based on this idea, an improved nonlinear split window model suitable for VIIRS(visible infrared imaging radiometer) mid-infrared wave band is constructed to calculate the mid-infrared reflectance in the flare region of the southern Indian Ocean. Firstly, the limited relation of sea surface reflectivity in VIIRS M12 and M13 bands is obtained, and then the nonlinear split window algorithm is used to simulate the sea surface reflectivity. The uncertainty of the simulation model is 0.83. On this basis, the sea surface reflectivity of the selected sample region is calculated using the VIIRS M12 band (center wavelength 3.697 渭 m) solar flare region data. Then two methods are used to verify the accuracy of reflectivity. The accuracy is 0.29% and 0.23%, respectively. Assuming that the accuracy of the calculated reflectivity in M12 and M13 bands is 2.48% and 1.033%, respectively. The accuracy of the model is greatly improved, which shows that the model is effective and feasible for calculating the reflectivity of marine flare region in VIIRS M12 mid-infrared band, and its precision can meet the requirements of mid-infrared sea reflectivity as the calibration datum between bands.
【作者单位】：北京大学空间信息集成与3S工程应用北京市重点实验室;国家卫星气象中心;
【基金】：博士点基金项目(20130001110046)资助
【分类号】：P182.52

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