Two-dimensional, high spatial resolution, solar spectroscopy using a correlation tracker. I. Correlation tracker description.

Ballesteros, E.; Collados, M.; Bonet, J. A.; Lorenzo, F.; Viera, T.; Reyes, M.; Rodriguez Hidalgo, I.
Bibliographical reference

Astronomy and Astrophysics Supplement, v.115, p.353

Advertised on:
2
1996
Number of authors
7
IAC number of authors
7
Citations
57
Refereed citations
43
Description
In this paper the description of the Solar Correlation Tracker prototype built by the Instituto de Astrof isica de Canarias is presented. The system is mainly conceived as a solar image tranquilizer, although a scanning utility has also been included in order to displace the image on the final focal plane with sub-arcsecond steps, thus allowing to perform two-dimensional high spatial resolution spectroscopy. The behaviour of the different elements of the tracker is shown, as well as their influence in the performance of the system. The restrictions of the Absolute Differences algorithm, used to detect image motion when granulation fields are considered, are extensively discussed. Laboratory and telescope tests have demonstrated the capabilities of the system. The electronic components have been adapted to new optics and mechanics developed at the Kiepenheuer Institut to build an Advanced Solar Correlation Tracker. The final version of the system has been installed at the German VTT of the Spanish Observatorio del Teide. The tests carried out have demonstrated that a bandwidth of about 60Hz (for an attenuation factor of two) is achieved, which is approximately four times larger than that of previous Correlation Trackers, at the same level of attenuation.