Accession Number : AD0681374

Title :   IMAGE ENHANCEMENT WITH PROLATE SPHEROIDAL WAVE FUNCTIONS.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Brown,Henry A.

Report Date : 29 NOV 1968

Pagination or Media Count : 53

Abstract : If the electric field intensity in the Fraunhofer region of a one-dimensional radiating source can be represented as a finite Fourier transform of the source current, then the source current can be reconstructed exactly by using prolate spheroidal wave functions and a segment of either the far field or the diffraction-limited image for the noise-free case. An example of the image enhancement of this process is given for the case of two equal point sources, which are unresolved in the Rayleigh sense. The point response function of this process shows that the resolution cell extent can be readily reduced to less than 10% of the Rayleigh cell with only 20 degrees of enhancement processing. A method of generating the Legendre polynomial and power series expansions of the prolate spheroidal angle functions of the first kind and order zero was worked out in detail. The Legendre polynomial expansion coefficients for degrees n = 0(1)40 and the power series expansion coefficients for degrees n = 0(1)36 are tabulated for c = 2. (Author)

Descriptors :   (*RADAR IMAGES, *WAVE FUNCTIONS), RADAR CROSS SECTIONS, RESOLUTION, INTEGRAL TRANSFORMS, DIFFRACTION, POLYNOMIALS, POWER SERIES, TABLES(DATA)

Subject Categories : Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE