Data Scanning Fast Fourier Transform.

Abstract : Fourier Transformation techniques find a variety of applications in modern engineering and science problems. The report describes the formulation and use of an economical Fast Fourier Transform to be applied to sampled data time series. The Fast Fourier Transform algorithm is derived and the implications and subtleties of its application are discussed. Common errors committed in the use of the Fast Fourier Transform are discussed and demonstrated. Methods which may be employed to avoid some common errors are presented. A unique algorithm allowing rapid application of the FFT has been developed and is described. This algorithm, called a Data Scanning Fast Fourier Transform (DSFFT), makes use of a computer scope, CAL-COMP plotter and medium-sized computer to obtain rapid Fourier Transformations of visually identified sections of time series. (Author)