Accurate estimation of the backscattering coefficient by light scattering at two backward angles

Backscattering coefficients are frequently estimated from light scattering at one backward angle multiplied by a conversion factor. We determined that the shapes of the volume scattering functions (VSFs), particularly for scattering angles larger than 170 degrees, cause significant variations in the conversion factor at 120 degrees. Our approach uses the ratio of scattering at 170 degrees and at 120 degrees, which is a good indicator of the shape differences of the VSFs for most oceanic waters and wavelengths in the visible range. The proposed method provides significant accuracy improvement in the determination of the backscattering coefficients with a prediction error of 3% of the mean. (C) 2015 Optical Society of America