The use of correlation matrices to estimate the number of uncorrelated frequency steps of the reverberation chamber field is presented and discussed. Finite-difference time-domain simulations of an actual reverberation facility are performed through an in-house parallel code. The efficiency of this code allows for capturing the field behavior through large spatial volumes. Spatial field samples are used to construct the multivariate correlation function and to evaluate the number of uncorrelated frequencies over a broad band. Results are obtained for single rectangular component and total field. It is found that traditional (autocorrelation based) methods tend to overestimate the number of uncorrelated frequency steps, with respect to the p...