The finite Fourier transform definition of an edge on the solar disk.
Abstract
A technique for locating the edge of the sun is proposed. The technique uses a finite Fourier transform of the observed limbdarkening function to achieve reduced sensitivity to atmospheric and instrumental effects and heightened sensitivity to the shape of the intrinsic limbdarkening function. A theory is developed that predicts these sensitivities. In order to facilitate wider application, general relations are calculated. A testing program which complements the theory is also reported. The location of the edge is shown to be influenced only by solar phenomena down to the milliarcsecond range.
 Publication:

The Astrophysical Journal
 Pub Date:
 September 1975
 DOI:
 10.1086/153814
 Bibcode:
 1975ApJ...200..484H
 Keywords:

 Atmospheric Effects;
 Fourier Transformation;
 Instrument Errors;
 Limb Darkening;
 Mathematical Models;
 Solar Limb;
 Gauss Equation;
 Graphs (Charts);
 Hermitian Polynomial;
 Integral Equations;
 Taylor Series;
 Transfer Functions;
 Solar Physics