[122] Sampling above Nyquist with high resolution

R F McLean 

This paper discusses a technique to enable high accuracy resolution of low- and high-frequency components and additionally frequencies above the Nyquist limiting condition. It discusses the method used to obtain accuracies to a fraction of a Hz over the complete frequency range. It has been in continuous operation on an industrial steam turbine for numerous years and has provided a detailed analysis of issues not attainable through any other form of on-site monitoring.