准确大气辐射传输下的水体辐射传输研究与应用

HydroLight which is the de-facto standard for water radiative transfer computation, is widely used, e.g., the quick and easy correction method for above-water remote sensing reflectance measurement[Mobley, 1999a], the angular correction model for water-leaving radiance[Lee, et al., 2011], and diffuse attenuation coefficients models[Lee, et al., 2005b; Lee, et al., 2005c], are all developed based on HydroLight simulation dataset. Radiative transfer of water is a coupled problem with that of atmosphere, however, HydroLight has several limitations in atmosphere radiative transfer part (see the following section for more details). Correction method of water reflected light and the water apparent optical properties(AOPs) (e.g., remote sensing reflectance Rrs, irradiance reflectance just beneath the water surface R, and all kinds of diffuse attenuation coefficients Kd) models are all related to light distribution, those models and conclusions need to be further investigated due to HydroLight cons. Improvements of those light field models also benefit the ecosystem modeling. This project will develop an end-to-end coupled atmosphere-water system HydroDOM to solve the HydroLight cons. Effects of atmosphere radiance distribution and coupling/non-coupling will be analyzed based on HydroDOM; The quick and easy correction method for above-water remote sensing reflectance measurement[Mobley, 1999a] will be improved; and the diffuse attenuation coefficients models will be further revised[Lee, et al., 2005b; Lee, et al., 2005c]. HydroDOM can also be used in airborne/satellite-borne sensors data simulations, and this project will benefit our new generation ocean color sensors.

HydroLight（HL）是水体辐射传输计算的事实标准，得到了广泛应用。如, 水体光谱测量中普遍采用简单校正法，二向性反射校正模型、漫射衰减系数物理模型等均基于HL模拟数据开发。但水体辐射传输问题研究离不开大气，而HL在大气辐射传输计算方面存在几个不足。水表反射光的校正及表观光学量与大气辐射密切相关，这些模型和结论的适用性需要进一步研究，并且光场模型改进对于提高生态系统模型中光学部分计算具有重要意义。 本项目主要针对HL在大气辐射传输计算方面的不足，研制准确大气辐射辐射下的大气-水体耦合辐射传输模型HydroDOM。在此基础上定量分析大气辐射计算模型及耦合/非耦合模式对水体辐射传输模拟的影响；改进目前水体光谱测量中天空反射光普遍采用的简单校正法；修订水体漫射衰减系数物理模型。本项目研究成果可直接应用于更为准确大气辐射条件下的水色卫星遥感数据的模拟，并为发展我国新一代水色卫星打下理论基础。

本项目主要针对HydroLight在大气辐射传输计算方面的不足，研制了更加准确大气辐射辐射下的大气-水体一体化耦合辐射传输模型HydroDOM。在此基础上改进了目前水体光谱测量中天空反射光普遍采用的简单校正法[Mobley, 1999a]；修订水体遥感反射和漫射衰减系数物理模型[Lee, et al., 2005b; Lee, et al., 2005c]。本项目研究成果已经应用于我国海洋2号水色卫星的定标与大气校正。