目的 现有关于漫衰减系数的研究大多是在490 nm波段建立反演模型,且未将相关研究与机载激光雷达测深能力建立联系,本文尝试获取测深参数532 nm漫衰减系数K_d(532)和透明度SD(Secchi disk depth),为机载双色激光雷达测深能力的评估和飞行方案的制定提供了重要技术参数。方法 首先分析了测深参数532 nm漫衰减系数K_d(532)和透明度SD对于评估机载双色激光系统测深能力的重要性。利用2003年春季中国黄东海区域的实测光学数据,对现有的漫衰减系数反演模式进行改进,建立了K_d(532)和K_d(490)=的线性关系以及SD和K_d(532)的幂函数关系。结果 根据2003年春季MODIS的490 nm漫衰减系数产品和上述函数关系获取了K_d(532)和SD参数。结论 本文获取测深参数K_d(532)和SD的方法能够用来有效评估该区域机载激光雷达的测深能力,准确性和精度依赖于实测光学数据的精度、分布和数量以及MODIS的K_d(490)产品的准确性。

Objective Current research on the 490 nm diffuse attenuation coefficient are mostly about the building of inversion model at 490 nm band, but has no connection with airborne LIDAR hydrographic ability. This study attempts to determine the hydrographic parameters K_d(532) and SD, which could be used to estimate the ability of the airborne double-color hydrographic LIDAR system and the important parameters for the flying scheme. Method First, the importance of the diffuse attenuation coefficient K_d(532) and SD as the hydrographic parameters for the airborne double-color hydrographic LIDAR system is analyzed. Then, according to the in situ measured data in the Yellow Sea and East China Sea coastal areas and the existing diffuse attenuation coefficient retrieval algorithms modified in this study, the linear correlation of K_d(532) and K_d(490) and the exponential correlation of SD and K_d(532) are derived. Result Based on the Moderate Resolution Imaging Spectroradiometer(MODIS) K_d(490) products and the aforementioned functions, the hydrographic parameters K_d(532) and SD are obtained. Conclusion The hydrographic parameters derived by the method employed in this study can be used availably to estimate hydrographic ability, whose accuracy depends on the accuracy, distribution, and quantity of measured optical data and the accuracy of MODIS K_d(490) products.