
Accession Number : AD0779874
Title : Asymptotic Distribution of the Discrete Transform of a Nonuniformly Sampled Multidimensional Process.
Descriptive Note : Interim rept.,
Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C
Personal Author(s) : Swick,David A.
Report Date : 03 MAY 1974
Pagination or Media Count : 20
Abstract : Multidimensional discrete transforms that map arbitrarily spaced sampled data into arrays of coefficients of arbitrary basis functions were considered in a previous paper. These studies are motivated by a model of observations uniformly spaced in time obtained simultaneously at a nonuniform set of spatial points. For the uniformly spaced samples the transformation becomes the familiar discrete finite Fourier transform (DFT), and fastFouriertransform processing is applicable. The nonuniformly spaced samples generally require a transformation matrix that is not as highly factorable. For a twodimensional sample space consisting of M nonuniform spatial points and N uniform temporal points, an efficient transformation is possible if M << N. Under the same assumption this twodimensional transformation will be shown to approximately diagonalize the covariance matrix. 'Asymptotic' will refer here to the limit as N nears infinity, with M finite.
Descriptors : *Signal processing, *Fourier transformation, Information theory, Stochastic processes, Time series analysis, Matrices(Mathematics), Asymptotic series, Sampling
Subject Categories : Cybernetics
Distribution Statement : APPROVED FOR PUBLIC RELEASE