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Proceedings Paper • Open Access

High accuracy absolute distance metrology
Author(s): Bas L. Swinkels; Nandini Bhattacharya; Ad L. Verlaan; Joseph J. M. Braat

Paper Abstract

One of ESA’s future missions is the Darwin Space Interferometer, which aims to detect planets around nearby stars using optical aperture synthesis with free-flying telescopes. Since this involves interfering white (infra-red) light over large distances, the mission is not possible without a complex metrology system that monitors various speeds, distances and angles between the satellites. One of its sub-systems should measure absolute distances with an accuracy of around 70 micrometer over distances up to 250 meter. To enable such measurements, we are investigating a technique called frequency sweeping interferometry, in which a single laser is swept over a large known frequency range. Central to our approach is the use of a very stable, high finesse Fabry-P´erot cavity, to which the laser is stabilized at the endpoints of the frequency sweep. We will discuss the optical set-up, the control system that controls the fast sweeping, the calibration and the data analysis. We tested the system using long fibers and achieved a repeatability of 50 micrometers at a distance of 55 meters. We conclude with some recommendations for further improvements and the adaption for use in space.

Paper Details

Date Published: 21 November 2017
PDF: 7 pages
Proc. SPIE 10567, International Conference on Space Optics — ICSO 2006, 105670Z (21 November 2017); doi: 10.1117/12.2308057
Show Author Affiliations
Bas L. Swinkels, Technische Univ. Delft (Netherlands)
Nandini Bhattacharya, Technische Univ. Delft (Netherlands)
Ad L. Verlaan, TNO (Netherlands)
Joseph J. M. Braat, Technische Univ. Delft (Netherlands)

Published in SPIE Proceedings Vol. 10567:
International Conference on Space Optics — ICSO 2006
Errico Armandillo; Josiane Costeraste; Nikos Karafolas, Editor(s)

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