VLTI Configurations Overview
P96 and following periods
The offered AT quadruplets available for service and visitor mode in P96 are different from the ones offered in P94. The new configurations were chosen combining operational constraints and an optimized sky and u,v coverage. For periods following P96, the quadruplets are presented in the figure below, alongside two figures showing the sky and uv coverage for a 4h observation of a star at -15º.
P98 and following periods
The introduction of GRAVITY comes with a slight complication: in dual feed mode, GRAVITY can only be operated with AT all south of the delay line tracks. As such, the current Large (A0-G1-J2-J3) and Medium (K0-G2-D0-J3) *cannot* be used in dual feed. As such, dual feed observations of GRAVITY will be executed either with the Small (A0-B2-D0-C1) or the "all south" Large (A0-G1-J2-K0) configurations.
Configurations offered using the Unit Telescopes:
AMBER is offered on all four available UT triplets:
Configurations offered using the Auxiliary Telescopes:
The users are requested to provide their preferred AT quadruplet in their proposal at phase 1. The quadruplet cannot be changed after proposal submission. In case of the 3 telescope instrument AMBER, the triplet used on sky is set by the OB preparation process in phase 2 (for service mode proposals) and during the run itself for visitor mode observations.
AMBER is offered with the 12 unique triplets: