ESS210B
Prof. Jin-Yi Yu
Resolution of Spectrum - Bandwidth
qBandwidth (Df)= width of the frequency band è resolution of spectrum
q     Df = 1/N (cycle per time interval)
qFor example, if a time series has 900 monthly-mean data:
q     bandwidth = 1/900 (cycle per month).
q     Nyquist frequency = ½ (cycle per month)
q     Total number of frequency bands = (0-Nyquist frequency)/bandwidth
q                                                            = (0.5)/(1/900) = 450 = N/2
q     Each frequency band has about 2 degree of freedom.
qIf we average several bands together, we increase the degrees of freedom but reduce the resolution (larger bandwidth).