An algorithm for estimating the power spectral density and the correlation function of laser Doppler-generated data sets is introduced. The algorithm is of the type of direct spectral estimators including weighting of individual velocity values to correct statistical biases caused by the correlation of instantaneous data rate and velocity values. It is extended by the forward–backward inter-arrival time weighting, the correction of the wraparound error, that of dead-time influences, and an error due to the removal of estimated block mean values. A temporal limitation of the correlation function as an alternative to the block averaging allows the block lengths to be chosen in a wide range with less necessities for compromises between systematic and random errors.