NEAT is an astrometric mission proposed to ESA with the objectives ofdetecting Earth-like exoplanets in the habitable zone of nearby solar-typestars. NEAT requires the capability to measure stellar centroids at theprecision of 5e-6 pixel. Current state-of-the-art methods for centroidestimation have reached a precision of about 2e-5 pixel at two times Nyquistsampling, this was shown at the JPL by the VESTA experiment. A metrology systemwas used to calibrate intra and inter pixel quantum efficiency variations inorder to correct pixelation errors. The European part of the NEAT consortium isbuilding a testbed in vacuum in order to achieve 5e-6 pixel precision for thecentroid estimation. The goal is to provide a proof of concept for theprecision requirement of the NEAT spacecraft. The testbed consists of two main sub-systems. The first one produces pseudostars: a blackbody source is fed into a large core fiber and lights-up apinhole mask in the object plane, which is imaged by a mirror on the CCD. Thesecond sub-system is the metrology, it projects young fringes on the CCD. Thefringes are created by two single mode fibers facing the CCD and fixed on themirror. In this paper we present the experiments conducted and the resultsobtained since July 2013 when we had the first light on both the metrology andpseudo stars. We explain the data reduction procedures we used.
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