Angular scattering functions of algae and silt: An analysis of backscattering to scattering fraction

In order to obtain more information on the angular scattering behaviour of algae and silt research was initiated to determine whether or not the volume scattering functions by Petzold (7)for the San Diego Harbour are appropriate for use in other types of turbid waters as is often stated in literature. This paper presents a selection of the measured angular scattering distribution functions (ASD; scaled at the 90 degrees scattering angle) over the range 15 degrees-165 degrees,the extrapolated angular scattering distribution functions extended to the range of 0 degrees - 180 degrees by fitting Mie functions and the calculated (partial) backward scattering to total scattering ratios (backscattering fractions). The San Diego Harbour measurements by Petzold (7), may not be applied to other turbid waters; it is in the backscattering region where the samples deviate most from the San Diego ASD (calculated from his VSF) from Petzold (7). A large addition to existing literature values for (partial) backscatter probabilities is presented for 14 freshwater and marine algal species samples and 2 estuarine silt samples.