Evaluation of four MERIS atmospheric correction algorithms in Lake Kasumigaura, Japan

Abstract

Accurate atmospheric correction for turbid inland waters remains a significant challenge. Several atmospheric correction algorithms have been proposed to address this issue, but their performance is unclear in regard to Asian lakes, some of which have extremely high turbidity and different inherent optical properties from lakes in other continents. Here, four existing atmospheric correction algorithms were tested in Lake Kasumigaura, Japan (an extremely turbid inland lake), using in situ water-leaving reflectance and concurrently acquired medium resolution imaging spectrometer (MERIS) images. The four algorithms are (1) GWI (the standard Gordon and Wang algorithm with an iterative process and a bio-optical model) (2) MUMM (Management Unit of the North Sea Mathematical Models); (3) SCAPE-M (Self-Contained Atmospheric Parameters Estimation for MERIS Data) and (4) C2WP (Case-2 Water Processor). The results show that all four atmospheric correction algorithms have limitations in Lake Kasumigaura, even though SCAPE-M and MUMM gave acceptable accuracy for atmospheric correction in several cases (relative errors less than 30% for the 2006 and 2008 images). The poor performance occurred because the conditions in Lake Kasumigaura (i.e. the atmospheric state and/or turbidity) did not always meet the assumptions in each atmospheric correction algorithm (e.g. in 2010, the relative errors ranged from 42% to 83%). These results indicate that further improvements are necessary to address the issue of atmospheric correction for turbid inland waters such as Lake Kasumigaura, Japan.

Acknowledgements

The authors would like to acknowledge Dr L. Guanter, who developed the SCAPE-M algorithm and performed atmospheric correction of SCAPE-M on the MERIS images used in this study. The authors would also like to thank the two anonymous referees for their valuable and useful comments on the manuscript.

Funding

This research was supported in part by the Grants-in-Aid for Scientific Research of MEXT from Japan [No. 25420555 and No. 23404015], and also by the Environment Research and Technology Development Fund [S–9–4–(1)] of the Ministry of the Environment, Japan.