Data reduction methods for single-mode optical interferometry^*

Application to the VLTI two-telescopes beam combiner VINCI

¹ LESIA, UMR 8109, Observatoire de Paris-Meudon, 5 Pl. Jules Janssen, 92195 Meudon Cedex, France e-mail: Pierre.Kervella@obspm.fr
² European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19, Chile
³ Observatoire de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland

Received: 22 October 2003
Accepted: 14 June 2004

Abstract

The interferometric data processing methods that we describe in this paper use a number of innovative techniques. In particular, the implementation of the wavelet transform allows us to obtain a good immunity of the fringe processing to false detections and large amplitude perturbations by the atmospheric piston effect, through a careful, automated selection of the interferograms. To demonstrate the data reduction procedure, we describe the processing and calibration of a sample of stellar data from the VINCI beam combiner. Starting from the raw data, we derive the angular diameter of the dwarf star α Cen A. Although these methods have been developed specifically for VINCI, they are easily applicable to other single-mode beam combiners, and to spectrally dispersed fringes.