A new wavelet-based approach for the automated treatment of large sets of lunar occultation data^*

¹ Departament d'Astronomia i Meteorologia, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona, Spain e-mail: ofors@am.ub.es
² Observatori Fabra, Camí de l'Observatori s/n, 08035 Barcelona, Spain
³ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany e-mail: arichich@eso.org
⁴ Computer Vision Center, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
⁵ Departament de Ciències de la Computació, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain

Received: 4 November 2007
Accepted: 15 December 2007

Abstract

Context.The introduction of infrared arrays for lunar occultations (LO) work and the improvement of predictions based on new deep IR catalogues have resulted in a large increase in sensitivity and in the number of observable occultations.

Aims.We provide the means for an automated reduction of large sets of LO data. This frees the user from the tedious task of estimating first-guess parameters for the fit of each LO lightcurve. At the end of the process, ready-made plots and statistics enable the user to identify sources that appear to be resolved or binary, and to initiate their detailed interactive analysis.

Methods. The pipeline is tailored to array data, including the extraction of the lightcurves from FITS cubes. Because of its robustness and efficiency, the wavelet transform has been chosen to compute the initial guess of the parameters of the lightcurve fit.

Results.We illustrate and discuss our automatic reduction pipeline by analyzing a large volume of novel occultation data recorded at Calar Alto Observatory. The automated pipeline package is available from the authors.