  The effect of a random phase screen on laser beam wander in a turbulent
atmosphere is studied theoretically. The method of photon distribution function
is used to describe the photon kinetics of both weak and strong turbulence. By
bringing together analytical and numerical calculations, we have obtained the
variance of beam centroid deflections caused by scattering on turbulent eddies.
It is shown that an artificial distortion of the initial coherence of the
radiation can be used to decrease the wandering effect. The physical mechanism
responsible for this reduction and applicability of our approach are discussed.
