The SOIRDETE (Synthese d'Ouverture en Infra Rouge avec DEux TElescopes) infrared interferometry instrument at the Obervatoire de la Cote d'Azur in France is described. The basic principles of the instrument are set forth and the nature of the data it provides is explained. The design and operation mode of the instrument are examined together with its measurement procedure. A preliminary result from the instrument on Alpha Orion is reported which indicates the possible existence of an additional shell of dust surrounding the central star.
"Infrared interferometry at Observatoire de la Cote d'Azur, France", Proc. SPIE 1341, Infrared Technology XVI, (1 November 1990); doi: 10.1117/12.23089; https://doi.org/10.1117/12.23089