%0 Conference Proceedings %T Global astrometry with OSI %+ Centre National d’Études Spatiales [Paris] (CNES) %+ Laboratoire d'Astrophysique de Grenoble (LAOG) %A Loiseau, Sacha %A Malbet, Fabien %A Yu, Jeffrey W. %< avec comité de lecture %B Proc. SPIE Vol. 2477 %C à renseigner, Unknown Region %V 2477 %P 259-266 %8 2023-03-14 %D 2023 %Z 1995SPIE.2477..259L %R 10.1117/12.212997 %Z Sciences of the Universe [physics]Conference papers %X We present a method for performing global astrometry with the proposed Orbiting Stellar Interferometer. Because it is dedicated to wide-angle astrometry, OSI has the intrinsic capabilities to achieve global astrometry, even though it doesn't measure directly relative angles between pairs of stars, such as HIPPARCOS. In this paper, a time-independent model is shown, leading to a coherent solution for the positions of reference stars on the whole sky. With an initial measurement accuracy of 10 micro-arcseconds, corresponding to an accuracy of 340 picometers in the knowledge of the delay-line position of the observing interferometer, the consistent least-squares solution gives an accuracy by which the astrometric parameters can be obtained around 2 - 3 micro-arcseconds. %G English %L insu-04029173 %U https://insu.hal.science/insu-04029173 %~ INSU %~ UGA %~ CNRS %~ UNIV-GRENOBLE1 %~ CNES %~ OSUG %~ LAOG