Accession Number : AD0720198

Title :   Some Aspects of the Harmonic Analysis of Irregularly Spaced Data.

Descriptive Note : Technical rept.,

Corporate Author : ATMOSPHERIC SCIENCES LAB WHITE SANDS MISSILE RANGE N MEX

Personal Author(s) : Avara,Elton P. ; Kays,Marvin

Report Date : NOV 1970

Pagination or Media Count : 43

Abstract : An investigation into the effect of irregular spacing of data upon harmonic coefficients is presented. The statistical model for the irregularity of the spacing is subject to certain constraints. The coefficients of each harmonic are calculated individually using regression analysis. When the data does not contain a particular harmonic, the unequal spacing will usually cause the computed amplitude to be nonzero, and its value will vary statistically as a multiple of a Rayleigh variable. The multiplier is a function of the amplitudes, phases and frequencies of the actual harmonics in the data and the frequency of the harmonic under investigation. When the data consists entirely of Gaussian random noise, the multiplier is not greatly affected by frequency and may be considered constant. The effects of various input data upon the expected values of some harmonic amplitudes are presented in tables for comparison purposes. The concept of complete folding is replaced by partial folding or no folding at all depending upon the spacing involved. (Author)

Descriptors :   (*STATISTICAL DATA, *HARMONIC ANALYSIS), REGRESSION ANALYSIS, PROBABILITY DENSITY FUNCTIONS, DISTRIBUTION THEORY, RANDOM VARIABLES, MATRICES(MATHEMATICS)

Subject Categories : Statistics and Probability

Distribution Statement : APPROVED FOR PUBLIC RELEASE