Image reconstruction by redundant spacing calibration with a 3-telescope optical interferometer: constraints on the delay fines

CHARON-III is a three-telescope optical interferometer project dedicated to high angular resolution imaging. In optical interferometry, the delay lines compensate the optical path difference between different arms of the interferometer. To reconstruct an image without any a priori knowledge of the object, we use the phase closure imaging with the redundant spacing calibration technics. This implies constraints on the configurations of the telescopes array, and therefore on the offsets and the kinematics of the delay lines. We have studied their motion to define the future layout of the interferometer and the operational procedure.