Realization of Celestial Reference Frames using the Allan Variance Classification
Résumé
Recently te{GattanoLambertLeBail2018}, a new classification of VLBI radio sources was built on the basis of their astrometric stability revealed by the use of the Allan standard deviation. In such a classification, sources are divided into three groups depending on the nature of the noise content in the astrometric time series. The global level of noise then orders sources within each group. In this proceedings, we present several strategies on the basis of this classification to realize celestial reference frames, i.e. for selecting the set of defining sources used to define the fundamental axes of the frame. This set of sources is usually constrained in the data reduction by a no-net rotation constraint. Using two tools developed to determine the stability of realized frames, one that analyzes the stability of the annual realizations of a given frame and another that analyzes the coherence of random sub-frames, we determine the best usage of this classification.