Band shifting for ocean color multi-spectral reflectance data

An approach to perform band shifting applied to multi-spectral ocean remote sensing reflectance R-RS values in the visible spectral range is presented. The band-shifting scheme aims at expressing R-RS at a wavelength not originally part of the spectrum from data at neighboring bands. The scheme relies on the determination of inherent optical properties (IOPs) by a bio-optical model, the calculation of the IOPs at the target wavelength using the spectral shapes assumed for each IOP, and the operation of the bio-optical model in forward mode to express R-RS at the target wavelength. The performance of the band-shifting scheme applied to bands typical of satellite missions is assessed with hyper-spectral data sets obtained from radiative transfer simulations or from field measurements. The relative error epsilon on the conversion factors from 488 to 490 nm is mostly within 1%. Analogous results are obtained for conversions in the red spectral domain (665, 667 and 670 nm) only for synthetic data sets. The range of e for conversions between green bands (547, 555 and 560 nm) is within 2% to 5% depending on the data set considered. Similar results are obtained when R-RS values are computed at 510 nm from data at 488 and 531 nm. In the case of the assessment with simulated data, all band-shifting operations are characterized by an e range within 2% for all conversions when the concentration of chlorophyll-a is lower than 1 mg m(-3). Applied to satellite data, the band-shifting scheme noticeably improves the agreement between R-RS data from different missions. (C) 2015 Optical Society of America