Show that a result equivalent to that of Eq. 7.42, to determine the singly scattered spectrum, can also be accomplished by two measurements, only one of which invokes a polarizer: the backscattered light without a polarizing filter, and the backscattered light through a polarizing filter that is perpendicular to the illuminated polarization (calibrated for the transmision efficiency of the polarizer.) 15.1 = [5\" 1" 2 IS\" If. (7.42) 5.!" where, Is'lz singly scattered light