Empirical algorithm to estimate the average cosine of underwater light field at 490 nm

Abstract

The average cosine of the underwater light field µ(λ), where λ is wavelength, is an apparent optical property that describes the angular distribution of radiance at a given point in water. Here we present a simple algorithm to determine the average cosine at 490 nm, μ(490), which was developed using the measured optical parameters from the eastern Arabian Sea and coastal waters off Goa. The algorithm is validated using measured optical parameters. This algorithm, based on a single optical parameter, performed better compared to other empirical algorithms to determine average cosine of underwater light field. The absorption coefficient at 490 nm, derived as an application of μ(490), compared well with the synthetic optical data and optical data measured from other regions.