Investigations of High Resolution Imaging through the Earth's Atmosphere Using Speckle Interferometry
Abstract
Speckle interferometry is a post-detection image processing technique for producing diffraction limited data using large astronomical telescopes in the presence of Earth's turbulent atmosphere which otherwise limits the imaging resolution. The Steward Observatory digital video speckle interferometry system consists of subsystems for a) video digitization of intensified, magnified, focal-plane images, b) Fourier transform (or autocorrelation) signal processing, and c) image analysis to produce the final interpreted results. Speckle interferometry has now been shown capable of yielding diffraction images for objects as faint as visual magnitude 16. Objectives of present developments are to improve a) the resolution (by using the Multiple Mirror Telescope with its 6. 9m optical aperture), b) the accuracy of the derived results (by implementing better photon detection and recording devices), and c) the efficiency and speed of the reduction algorithms which extract the information (by means of high- speed digital signal-processing hardware). The work includes a growing effect in speckle image reconstruction using a combination of amplitude processing, various phase retrieval methods, holographic methods, and shift-and-add methods. The techniques have been applied to observations of Earth-orbiting satellites, asteroids, Pluto/Charon, binary stars, bright supergiant stars, active galactic nuclei, and quasi-stellar objects (QSOs). Originator-supplied keywords: Speckle interferometry; Image reconstruction; Optical interferometry, Phased optical arrays, MMT, Diffraction limited imaging, Speckle imaging.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 07, 1984
- Accession Number
- ADA150680
Entities
People
- E. K. Hege
- N. J. Woolf
- P. A. Strittmatter