Observatoire Aquitain des Sciences de l'Univers (OASU)
2, rue de l'Observatoire BP 89
SF2A-
33270
Floirac, France
Presentation 1 : None
PRIMA prospective (ASHRA)
G. Daigne
Starting from dual-field implementation on VLTI, key points in instrument control are identified.
Different instrumental set-up are proposed to investigate and overcome each one of these points:
an astrometric demonstrator with the test siderostats for control of the optical arm, phase-referencing
with 2 UTs for faint source imaging, ... Scientific objectives are also proposed as possible targets for each instrumental step.
Presentation 2 : None
Phase-referencing with short exposure and celestial reference frames (ASHRA)
G. Daigne, C. Ducourant and J.-F. Lestrade
Phase-referencing with short exposure is not limited to the isoplanatic
patch angle of a bright source, as long as differential piston is concerned. The potential of phase-referencing with 2 UTs is examined in terms of faint source magnitude and separation angle. Preliminary results show that ground-based optical interferometry will be one of the best candidate technique for linking the stellar sphere of a future space astrometry mission such as DIVA to the extragalactic reference frame (ICRF).