Abstract

Atmospheric turbulence limits the resolution of conventional astronomical observations through large ground-based telescopes to about 1". Recently, sub-arcsecond resolution has been achieved by estimating the complex spatial spectrum of a stellar object from a sequence of short-exposure images called specklegrams. Speckle interferometry (SI) gives the diffraction-limited modulus [1]. Phase-measuring processes are the Knox-Thompson (KT) [2], the closely related Phase-Gradient (PG) [3] and the Triple-Correlation (TC) [4] algorithms. Because of the narrow bandwidth, Δλ ≈ 10 nm, and short-exposure times, t_E ≈ 10 ms, the specklegrams of most stellar objects of interest contain less than 10³ photons. Consequently, it is advantageous to record the specklegrams as a list of photon addresses.

© 1989 Optical Society of America