Reference for frequency wavenumber filtering: Convectively Coupled Equatorial Waves: Analysis of Clouds and Temperature in the Wavenumber–Frequency Domain - MATTHEW WHEELER (1999)

I am trying to filter certain data (OLR, sst, lhf etc.) for waves (R1, Kelvin and MRG). How would it be different that just using a simple Lanczos filter for the periods of the respective waves.