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Quasi-Analytical Algorithms (QAAs) are based on radiative transfer equations and have been used to derive inherent optical properties (IOPs) from the above surface remote sensing reflectance (Rrs) in aquatic systems in which phytoplankton is the dominant optically active constituents (OACs). However, Colored Dissolved Organic Matter (CDOM) and Non Algal Particles (NAP) can also be dominant OACs in water bodies and till now a QAA has not been parametrized for these aquatic systems. In this study, we compared the performance of three widely used QAAs in two CDOM dominated aquatic systems which were unsuccessful in retrieving the spectral shape of IOPS and produced minimum errors of 350% for the total absorption coefficient (a), 39% for colored dissolved matter absorption coefficient (aCDM) and 7566.33% for phytoplankton absorption coefficient (aphy). We re-parameterized a QAA for CDOM dominated (hereafter QAACDOM) waters which was able to not only achieve the spectral shape of the OACs absorption coefficients but also brought the error magnitude to a reasonable level. The average errors found for the 400–750 nm range were 30.71 and 14.51 for a, 14.89 and 8.95 for aCDM and 25.90 and 29.76 for aphy in Funil and Itumbiara Reservoirs, Brazil respectively. Although QAACDOM showed significant promise for retrieving IOPs in CDOM dominated waters, results indicated further tuning is needed in the estimation of a(λ) and aphy(λ). Successful retrieval of the absorption coefficients by QAACDOM would be very useful in monitoring the spatio-temporal variability of IOPS in CDOM dominated waters. 相似文献
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传统载人测量船吃水深,无法进行浅海水深测量,因此吃水极浅的无人船为近海水深测量提供了新途径。本文利用无人船无验潮测深与GNSS网络RTK技术,在不同的风浪条件下进行了近海水深测量试验;并从轨迹跟踪与水深测量精度方面,定量评估了无人船野外作业的抗风浪能力。结果表明:0~0.3 m浪、0~2级风是无人船近海测量作业的理想风浪阈值;风浪过大会导致无人船路径跟踪精度较低,难以保证测量成果质量。在理想的风浪阈值内,无人船无验潮测深技术能实现近海水深的高精度测量,满足相关测深规范要求,在近海水深与海底地形测量中具有广阔的应用前景。 相似文献