Astron. Astrophys. Suppl. Ser.
Volume 138, Number 2, August 1999
|Page(s)||355 - 363|
|Published online||15 August 1999|
Astrometric optical interferometry with non-evacuated delay lines
Observatoire de Bordeaux, BP. 89, F–33270 Floirac, France e-mail: firstname.lastname@example.org
2 Dept. Arpèges, Observatoire de Paris-Meudon, F–92191 Meudon Cedex, France e-mail: email@example.com
Send offprint request to: G. Daigne
The effects of longitudinal dispersion in long baseline optical interferometry with non-evacuated delay lines are analyzed. A new technique is proposed for group delay tracking, with phase measurements in two wavebands only. Sensitivity and instrumental uncertainties are further investigated, together with the dependence on stellar color temperature. To a precision level of a few 10-10 rad, limiting factors in dual-field astrometry should be put under control with not too long interferometer baseline.
Key words: athmospheric effects / techniques: interferometric / astromety
© European Southern Observatory (ESO), 1999