Bandwidth in Time-Lag Correlation Method
q With the time-lag correlation method, the bandwidth of the
power spectrum is determined by the maximum time lag (L)
used in the calculation:
                  Df = 1 cycle/(2LDt).
q Number of frequency band = (Nyquist frequency – 0) / Df
                                                 = (2 Dt)-1 / (2L Dt)-1 = L
q Number of degrees of freedom = N/(number of bands)
                                                       = N/L