Canadian ASTRO‐H Metrology System

You are here: Homepage > Search

Canadian ASTRO‐H Metrology System

Koujelev, Alexandre / Gallo, Luigi C. / Gagnon, Stéphane

The Canadian Astro‐H Metrology System (CAMS) is the Canadian contribution to the Astro‐H X‐ray mission. It is a laser metrology system that is designed to measure lateral displacement of the hard X‐ray imaging detectors relative to their telescope axes caused by spacecraft manoeuvres and thermal changes in the 14 m space‐borne deployable optical bench. The CAMS measurements can be used to reconstruct images of stellar objects of interest for High Energy Astrophysics, such as black holes, supernova remnants, galaxies, and clusters of galaxies. The CAMS system is composed of an active part containing the laser and an imaging sensor and a passive part containing a retroreflector. The active part is installed near the X‐ray telescope and the passive is located 12 m away on the extendable optical bench near the X‐ray imager. The principle of CAMS measurement is based on determination of centroid location of the retroreflected laser beam. The key driving requirement of the design has been the stability in the accuracy of the CAMS measurement. The 0.24 mm, 3‐sigma accuracy is required across the entire operating temperature range that is ‐10 to +50 C for the active part and ‐20 to + 75 C for the passive part of CAMS. The development of two flight models meeting this key requirement took four years and has been completed with their delivery for integration with the Astro‐H spacecraft in 2015.