A comparison between different methods for the spectral analysis of experimentally obtained waveforms

Spectral analysis of functions obtained experimentally by three different methods is carried out. The methods are discrete Fourier transform (DFT), improved DFT, and a new method based on the classical Fourier analysis method. The analyzed waveforms are observed once as a sequence of samples (theoretical representation), and once as a sample and hold function (physical representation). The main points of the analysis are: calculation of the spectra using the different methods; obtaining approximated functions by the summation of the derived harmonics; and estimation of the errors in the approximation.<>