The MAMA Facility: A Survey of Scientific Programmes

Abstract

MAMA (Machine Automatique à Mésurer pour l’Astronomie) is a fast and accurate multichannel microdensitometer developed and operated by INSU and located at the Observatoire de Paris. MAMA processes in a few hours photographic plates up to 14″ × 14″ with a positional accuracy of 1μm (repeatability: 0.2μm) and a photometric accuracy of 2% over a dynamical range of 3 densities. The detector is a RETICON CCPD array with 1024 photodiodes. X and Y coordinates are measured with Heidenhain encoders. Autofocus is achieved through a maximisation of the plate grain noise, and is accurate to better than 4 microns. The plate can be digitised either in a systematic way by lanes 10.24 mm wide, or in a random access mode from a catalogue of preliminary positions. The basic pixel size (and sampling step) is 10μm. Oversampling down to 2μm can be used to digitise spectra; for some applications, pixels of 20, 30… 80 μm can be synthesized in real time.