Application of algorithms for high precision metrology
  This paper evaluates the performance of algorithms suitable to process the measurements from two laser beam metrology systems, in particular with reference to the Gaia Basic Angle Monitoring device. The system and signal characteristics are reviewed in order to define the key operating features. The low-level algorithms are defined according to different approaches, starting with a simple, model free method, and progressing to a strategy based on the signal template and variance. The signal model is derived from measured data sets. The performance at micro-arcsec level is verified by simulation in conditions ranging from noiseless to large perturbations. 
Mario Gai, Alberto Riva, Deborah Busonero, Raffaella Buzzi, Federico   Russo
astro-ph.IM