Diffraction-limited imaging with astronomical telescopes
Abstract
A theoretical investigation of a digital processing technique that can be used to obtain diffraction-limited images of stellar objects from large, ground-based astronomical telescopes, was performed. The input consists of a set of short-exposure photographs taken of an object over a short period of time. An averaging process which retains the phase information and suppresses the atmospheric noise is used, thereby removing the blurring caused by the atmospheric seeing. A diffraction-limited image of the object is then reconstructed by combining the phase and the modulus of the Fourier transform. The properties of the technique were analyzed theoretically using a Gaussian phase model to describe the atmospheric seeing. The effects of telescope aberrations on the technique were also considered. An extensive analysis has also been made on the effects of noise on the quality of the reconstructed images. A one-dimensional computer simulation was also performed.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1975
- Bibcode:
- 1975PhDT.........8K
- Keywords:
-
- Astronomical Photography;
- Diffraction Limited Cameras;
- Telescopes;
- Aberration;
- Atmospheric Turbulence;
- Atmospherics;
- Blurring;
- Computerized Simulation;
- Digital Techniques;
- Noise;
- Stars;
- Astronomy