The interfaces between the VLT Unit Telescopes and the scientific instruments to be operated at the VLT Cassegrain, Nasmyth and Coudé foci are well defined. Comprehensive documents exist which give all necessary details of these interfaces as well as other requirements with which the instruments and their control systems must comply.
Although the documents referred to hereafter have been prepared with great care it is necessary that Instrument Teams double-check with ESO (through the Instrument Responsible assigned to the instrument in question) all necessary details before designing critical items.
It is probably a good idea to get acquainted with the most common ESO acronyms when getting involved in the construction of an ESO instrument.
Second Generation VLT Instruments
Interface and numerous other relevant information for instrument builders is available in the "Requirements for Scientific Instruments on the VLT Unit Telescopes", ESO doc. no. VLT-SPE-ESO-10000-2723 issue 1 dated 18.03.2005. This document is valid for both Cassegrain and Nasmyth foci.
The VLT Observatory Requirements for Cassegrain Instruments (VLT doc. no. VLT-SPE-ESO-10000-0005 issue 2.0 dated 23.05.2001) and the VLT Observatory Requirements for Nasmyth Instruments (VLT doc. no. VLT-SPE-ESO-10000-0006 issue 2.0 dated 20.09.1995) are no longer valid.
We also make available here as separate pdf files with higher resolution than in the document appendix the applicable interface drawings for Cassegrain (ADWG-C) and Nasmyth (ADWG-N). Please note that the Nasmyth drawings have not yet been formally released. The information they contain is however correct.
- ADWG-C1 (UT section, b/w for A4 printing)
- ADWG-C1 (UT section, colour)
- ADWG-C2 (Cassegrain flange, b/w for A4 printing)
- ADWG-C2 (Cassegrain flange, colour)
- ADWG-C3 (Observing floor plan, b/w for A4 printing)
- ADWG-C3 (Observing floor plan, colour)
- ADWG-C4 (Instrument rotator, b/w for A4 printing)
- ADWG-C4 (Instrument rotator, colour)
- ADWG-N1 Nasmyth instrument flange A and rotator cross section
- ADWG-N2 Nasmyth instrument flange B and rotator cross section
- ADWG-N3 Nasmyth platform A: Top view and floor requirements
- ADWG-N4 Nasmyth interface flange A: Front view with telescope installations
- ADWG-N5 Nasmyth interface flange B: Front view with telescope installations
- ADWG-N6 Nasmyth platforms: Access and handling constraints
One Nasmyth focus at VLT-Antu (UT1) is reserved for "visitor instruments". For details about the purpose of this focus and how to propose an instrument click here. A dedicated document listing all requirements and interfaces for visitor instruments at the Nasmyth focus is currently in preparation. Until it is ready, please note the following:
- Requirements and recommendations specific for visitor instruments are described in Requirements for visitor instruments at UT Cassegrain foci (ps.gz, 450 kB, without drawings).
- The interface towards the Nasmyth focus (e.g. maximum mass, design space etc) is the same as for new facility scientific instruments (2nd generation instruments, see above)
- The applicable interface drawings are the same as for the Nasmyth focus (ADWG-N1-6), see above
Contact, further information
For additional information concerning the interfaces of particular instruments of the VLT second generation please address yourself to the instrument responsible of that instrument.
For specific interface information please contact Gero Rupprecht [at] eso.org