IMAGE ENHANCEMENT WITH PROLATE SPHEROIDAL WAVE FUNCTIONS.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 29, 1968
- Accession Number
- AD0681374
Entities
People
- Henry A. Brown
Organizations
- United States Naval Research Laboratory