Cost-effective multispectral three-mirrors anastigmat sensor for high-performance surveillance applications using electroformed free-form mirrors

A lightweight single-aperture and multi-spectral sensor operating from Visible to LWIR has been designed, manufactured and tested exploiting a Three Mirror Anastigmat (TMA) telescope featuring thin free-form mirrors electroformed from negative masters. Manufacturing complexity is in place only for the master realization, the contribution of which to the sensor cost decreases with the number of replicas. The TMA, suitable for airborne surveillance applications, has F/no. 1.4, focal length 136 mm and field of view 4.3° × 3.1°, and provides two channels, in the MWIR-LWIR and in the visible waveband. The nominal contrast is better than 75% in the visible at 25 cycles/mm. Electroformed 1 mm thick mirrors keep the sensor mass below 3 kg. Stray light and thermo-structural design has been done to comply with airborne conditions. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.