Multiple backscattering of pulsed light is formulated for linearly polarized incident radiation. The method is based on the selection of a particular geometry in which the primary and nth order backscattering return to the receiver simultaneously. It is shown that the returned power from water clouds at a range of 1 km due to orders of scattering higher than the second may be neglected in a collimated pulsed lidar system whose field of view is less than 10−2 rad.