Reconstruction of computer simulated, atmospheric turbulence-degraded, astronomical objects by application of the Knox-Thompson and triple-correlation phase recovery techniques

Abstract

Atmospheric turbulence severely degrades images of astronomical objects. Providing images that accurately reflect the true nature of these objects is essential to their understanding. Several object recovery techniques exist within the field of speckle imaging that produce accurate representations of astronomical objects. This thesis provides an in-depth comparison of two such techniques, Knox-Thompson and triple-correlation. Through computer simulation, this thesis accurately compares the abilities of both recovery techniques to enhance turbulence degraded objects by exploiting the diffraction-limited information contained in short exposure, or speckle, images. The simulation produced these images by creating an object and several phase screens which simulated the effects of turbulence. Together, the object and the appropriate quantity of phase screens yielded the required short exposure images. Application of the Knox-Thompson and triple-correlation techniques to identical sets of these degraded images produced the resulting reconstructed objects, their signal-to-noise ratios and their azimuthal RMS phase errors. Comparison of these three factors over several imaging criteria concluded that the superior phase recovery technique was triple-correlation.