FöRFATTARE
Alatalo, Johanna

DATUM
2001-12-12

INSTITUTION
Tillämpad fysik, maskin- och materialteknik / Fysik

SAMMANFATTNING
The European Southern Observatory is an intergovernmental organisation with its headquarters in Garching near Munich, Germany. It was founded in 1962 and operates astronomical observatories in Chile. Currently under construction is the Very Large Telescope Observatory on Cerro Paranal in the Atacama Desert in the northern part of Chile.

The VLT Observatory consists of four 8.2 metre mirror Unit Telescopes and, to begin with, three 1.8 metre mirror Auxiliary Telescopes. These can all be used individually for astronomical observations, but the goal is to connect two or more telescopes into an interferometer. To obtain fringes, it is important, that the wavefronts of the light from the different telescopes are matched at the combination in the VLTI Laboratory with no larger difference than one wavelength. This demand raises the expectation on the beam combining instrument quality and it is essential that it works together with the rest of the system and its software.

The VLTI simulation package was constructed to enable testing and development of new instrument software. Relevant parts of the VLTI Control Software have been simulated and a special simulation software module has been constructed. The focus of the simulation is the interaction between the VLTI Control Software and the VLTI Instruments Software, and not the internal processes of the VLTI Control Software.

The VLTI simulation package was tested together with the software of the VLT Interferometer Commissioning Instrument, VINCI, and worked properly. It was also tested together with VINCI Software and VINCI on Paranal in Chile at the beginning of 2001.

On March 17, 2001, observations were made with the VLTI, and fringes were successfully attained.

ISSN 1402-1617 / ISRN LTU-EX--02/034--SE / NR 2002:034