Image Reconstruction Using The Bispectrum*

The resolution of a standard telescope imaging system is severely limited by temperature-gradient induced phase fluctuations in the atmosphere. Short exposure images, however, during which the atmosphere is effectively frozen, contain diffraction-limited resolution information about the object. Techniques for extracting this information are collectively called "speckle interferometry". He will show that by averaging the complex bispectra of an ensemble of images, the Fourier phase of the object can be estimated. This estimate, combined with a standard estimate of the Fourier magnitude using the average power spectrum, will then yield a diffraction-limited reconstruction of the object. We also present results of a simulation of this technique, which demonstrates the reconstruction of an extended, noisy object from a series of short exposure images.