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 fast-Fourier-transform processing is applicable. The nonuniformly spaced samples generally require a transformation matrix that is not as highly factorable. For a two-dimensional 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 two-dimensional 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