Data reduction methods for single-mode optical interferometry Application to the VLTI two-telescopes beam combiner VINCI

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.

[1]  G. Perrin,et al.  A catalogue of calibrator stars for long baseline stellar interferometry , 2002 .

[2]  David Mouillet,et al.  AMBER: the near-infrared focal instrument for the Very Large Telescope Interferometer , 2000, Astronomical Telescopes and Instrumentation.

[3]  P. Kervella,et al.  Tests of stellar model atmospheres by optical interferometry. VLTI/VINCI limb-darkening measurements of the M4 giant ψ Phe , 2004 .

[4]  B. Krauskopf,et al.  Proc of SPIE , 2003 .

[5]  Sebastien Morel,et al.  Commissioning the VLT interferometer: from first fringes toward a general user facility , 2003, SPIE Astronomical Telescopes + Instrumentation.

[6]  Marc S. Sarazin,et al.  Atmospheric and internal turbulence measured on the Very Large Telescope Interferometer with VINCI , 2003, SPIE Astronomical Telescopes + Instrumentation.

[7]  John Davis,et al.  Limb-darkening corrections for interferometric uniform disc stellar angular diameters , 2000 .

[8]  S. Mallat.  A wavelet tour of signal processing , 1998 .

[9]  M. Farge.  Wavelet Transforms and their Applications to Turbulence , 1992 .

[10]  Sebastiano Ligori,et al.  10-μm interferometry on the VLTI with the MIDI instrument: a preview , 2000, Astronomical Telescopes and Instrumentation.

[11]  Leonardo Corcione,et al.  Fringe tracking for VLTI and LBT , 2003 .

[12]  Laurent Jocou,et al.  Increasing the imaging capabilities of the VLTI using integrated optics , 2003, SPIE Astronomical Telescopes + Instrumentation.

[13]  Andreas Glindemann,et al.  The VLT Interferometer: a unique instrument for high-resolution astronomy , 2000, Astronomical Telescopes and Instrumentation.

[14]  B. Efron.  Bootstrap Methods: Another Look at the Jackknife , 1979 .

[15]  S. Mallat.  VI – Wavelet zoom , 1999 .

[16]  A. Grossmann,et al.  Cycle-octave and related transforms in seismic signal analysis , 1984 .

[17]  F. Thevenin,et al.  The diameters of $\alpha$ Centauri A and B - A comparison of the asteroseismic and VINCI/VLTI views , 2003 .

[18]  M. Colavita.  Fringe Visibility Estimators for the Palomar Testbed Interferometer , 1998, astro-ph/9810462.

[19]  Mark R. Kidger,et al.  Spectral Irradiance Calibration in the Infrared. X. A Self-Consistent Radiometric All-Sky Network of Absolutely Calibrated Stellar Spectra , 1999 .

[20]  G. Perrin.  Subtracting the photon noise bias from single-mode optical interferometer visibilities , 2003 .

[21]  Wesley A. Traub,et al.  FLUOR fibered instrument at the IOTA interferometer , 1998, Astronomical Telescopes and Instrumentation.

[22]  Rafael Millan-Gabet,et al.  Integrated optics for astronomical interferometry IV. First measurements of stars , 2001 .

[23]  I. Daubechies.  Ten Lectures on Wavelets , 1992 .

[24]  Frederic Derie.  VLTI delay lines: design, development, and performance requirements , 2000, Astronomical Telescopes and Instrumentation.

[25]  Rainer Wilhelm,et al.  VINCI, the VLTI commissioning instrument: status after one year of operations at Paranal , 2003, SPIE Astronomical Telescopes + Instrumentation.

[26]  Gert Finger,et al.  ESO infrared detector high-speed array control and processing electronic IRACE , 1998, Astronomical Telescopes and Instrumentation.

[27]  Sebastien Morel,et al.  The VLTI -- A Status Report , 2003, SPIE Astronomical Telescopes + Instrumentation.

[28]  M. M. Colavita,et al.  Atmospheric Turbulence Measurements with the Palomar Testbed Interferometer , 2001, astro-ph/0102052.

[29]  Andreas Glindemann,et al.  VINCI: the VLT Interferometer commissioning instrument , 2000, Astronomical Telescopes and Instrumentation.

[30]  J.-M. Mariotti,et al.  Deriving object visibilities from interferograms obtained with a fiber stellar interferometer , 1997 .

[31]  C. Soubiran,et al.  Catalogue of [Fe/H] determinations for FGK stars: 2001 edition , 2001, astro-ph/0106438.

[32]  C. Basdevant,et al.  Wavelet spectra compared to Fourier spectra , 1995 .