There are currently no instruments for in situ measurement of the Muller matrix, although one measurement of the full matrix has been made in the laboratory on a sea water sample (Voss and Fry, 1984). Instruments are under development for measurement of selected elements of the Muller matrix, which if available would enable underwater polarized RT calculations to be made for three elements of the Stokes Vector.
Unique instruments do exist for underwater measurement of the Stokes Vector (Tonizzo et al., 2009). Although such measurements are not yet common, they likely will become more so in the future.
Doing unpolarized radiative transfer in both the ocean and the atmosphere and using scalar (unpolarized) RT codes results in errors in the order of 10 percent in predictions of TOA radiances as needed for development and validation of satellite sensors and atmospheric corrections algorithms. The magnitude and wavelength dependence of the errors depend on the atmospheric and oceanic properties, sun angle, and viewing direction. The errors therefore cannot be quantified without detailed vector (polarized) RT calculations for the particular environmental and viewing conditions of interest. Therefore, the development of a user-friendly and publicly available coupled ocean-atmosphere vector RT code would greatly benefit future ocean color sensor and algorithm development.