Velocity measurement of a diffuse object by using time-varying speckles

The relation between the velocity of a moving diffuse object and the mean number of integrated speckles in the certain time interval at the far-field plane of the object is obtained. By using this relation based on the first order statistics of integrated speckles, a new method of measuring the velocity of the diffuse object is proposed and experimentally verified. The first order probability density function of time-integrated speckles is also studied from which the validity of the present method is verified.