How is the angle determined in volume scattering function in water for a lidar application? The volume scattering function(VSF) for water is given by, VSF(teta) = A(lambda, S)*(1-cos power 2of teta(1-delta)/(1+delta)) where teta is the direction of scatterred radiation. A is amplitude lambda is wavelength S is salinity delta is depolarization ratio. How is scatterred direction angle taken for the measurement of VSF i.e. in what range of angles(0, 90,....etc)?