USE OF FOURIER-TRANSFORMS FOR ISOLATING COMPONENTS OF EXPERIMENTAL-DATA

Fourier transform techniques were used to analyse a time series of experimental data in order to isolate a repeatedly scanned component, periodic and non-periodic temporal components and noise. The method was applied to a rocket-home electrostatic electron energy analyser being swept at a fixed rate, but having the spectra modified by non-periodic temporal variations and modulation at the spin rate of the rocket. It was found that by suitable displacement of the data amplitude origin and shaping of the ends of the time series, a very good separation of the various components was obtained. This indicates that the technique is a method particularly applicable to analysing data in which different periodic components are present. © 1978.