  This paper presents a least mean square (LMS) algorithm for the joint
estimation of acoustic and mean flow velocities from laser doppler velocimetry
(LDV) measurements. The usual algorithms used for measuring with LDV purely
acoustic velocity or mean flow velocity may not be used when the acoustic field
is disturbed by a mean flow component. The LMS-based algorithm allows accurate
estimations of both acoustic and mean flow velocities. The Cram\'er-Rao bound
(CRB) of the associated problem is determined. The variance of the estimators
of both acoustic and mean flow velocities is also given. Simulation results of
this algorithm are compared with the CRB and the comparison leads to validate
this estimator.
