为实现高分2号图像(GF2)业务化大气校正,利用矢量6S模型(6SV)将辐射传输散射与吸收进行分离计算,其中散射部分采用涵盖各种大气模式、气溶胶类型、成像几何等条件下的大气校正查找表(look-up tables,LUTs)表示,大气吸收部分采用6SV拟合计算的6种大气模式下大气透过率的经验公式表示,这种处理有效简化了查找表大小.在内存4 GB、主频3.10 GHz条件下,通过比较基于本查找表方法和基于FLAASH大气校正软件对北京地区一景GF2数据处理.结果表明:以6SV模型直接大气校正法结果作为真值,两者的绝对误差分别为0.8%和2.6%,处理时间分别为77 s和240 s,该大气校正查找表在处理精度和效率更加适合业务化大气校正.%To accomplish operational atmospheric correction of GF-2 image, vector 6S codes were used to calculate scattering and absorption effects in the radiation transfer process, respectively. The former was stored in the look-up tables (LUTs), containing variety of combinations from the atmospheric models, aerosol types, imaging geometry, etc. The latter was expressed as the experience formulas of atmospheric transmittances, calculated in the conditions of six types of atmospheric models. The size of look-up tables was much reduced because of the separated treatment of scattering and absorption. Finally, under the computing test circumstance with 4 GB of RAM and 3. 10 GB of CPU frequency, the running status of the method based on LUTs was compared with that of the atmospheric correction software, FLAASH. Results show that the absolute errors and running time are 0. 8% and 2. 6%, 77 s and 240 s, respectively. It illustrates that the LUTs designed here is more suitable for operational image atmospheric correction given the advantage of accuracy and efficiency.
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