A study of a correlation tracking method to improve imaging quality of ground-based solar telescopes
Abstract
The measurement and correction of image motion introduced by the earth's atmosphere is undertaken, in order to improve solar imaging, by means of a correlation-tracking method designed to guide ground-based solar telescopes during the study of small scale, low contrast photospheric structures. A time series of digitized images was obtained with a two-dimensional CCD camera of 32 x 32 pixels. Image motion was determined from the locations of the cross-correlation function peaks of an arbitrarily chosen reference image, and the tracking method was simulated off-line by computer methods. Analysis results indicate that image motion may be suppressed to a residual rms value as low as 1/18th of the theoretical Rayleigh limit of telescopic resolution. The correlation method is found to work on arbitrary structures with rms constant values as low as a few percent under acceptable seeing conditions.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1983
- Bibcode:
- 1983A&A...119...85V
- Keywords:
-
- Cross Correlation;
- Image Motion Compensation;
- Optical Tracking;
- Solar Granulation;
- Solar Instruments;
- Telescopes;
- Atmospheric Effects;
- Fourier Transformation;
- Image Enhancement;
- Image Resolution;
- Scintillation;
- Time Series Analysis;
- Tracking Filters;
- Astronomy