Spectral proper orthogonal decomposition using multitaper estimates

The use of multitaper estimates for spectral proper orthogonal decomposition (SPOD) is explored. Multitaper and multitaper-Welch estimators that discrete prolate spheroidal sequences (DPSS) as data windows are compared to the standard SPOD algorithm exclusively relies on weighted overlapped segment averaging, or Welch's method, estimate cross-spectral density matrix. Two sets turbulent flow data, one experimental other numerical, used discuss choice resolution bandwidth bias-variance tradeoff. Multitaper-Welch combine both approaches by applying tapers overlapping segments allow flexible control resolution, variance, bias. At additional computational cost but same provide lower variance at fixed frequency higher similar algorithm.