Infrared pushbroom camera breadboard using off-the-shelf 2D array of detector

Abstract

Performances for nowadays optronic systems require focal plane arrays (FPA) with an increasing number of detectors. The `push- broom' technic is well adapted to earth observation in the visible range with the availability of long linear CCD'S offering thousands of pixels. In the infrared, line scan systems are preferred at the present time because technological difficulties have to be overcome in order to get long linear arrays. Among the most important, are: (1) Difficulties to have a large cold focal plane with a temperature uniformity of a few degrees. (2) Difficulties to get good detection material over large surface. Mechanical or optical butting technology can be used there but with dead pixels and/or side effects. (3) Very low cold shield efficiency due to the geometry of the long linear array. (4) Very high development costs. MATRA DEFENSE UAO has made the design of a new infrared FPA concept which has the advantage to overcome all drawbacks listed previously (patented design). The idea consists to transform the pixel arrangement geometry of a 2D array which is available off the shelf into a long linear FPA using a coherent infrared fiber optic reformatter. In order to demonstrate the feasibility of this new FPA concept, a camera breadboard has been built. This task has been supported by the French MOD (STTE). This paper describes this breadboard and gives main technical performances.