Design of image sensors for hyperspectral applications

The sensor design for Hyperspectral observation is significantly different to many other imaging applications and the various requirements are discussed. An early programme is the MERIS (Medium Resolution Imaging Spectrometer) instrument on ENVISAT, which has been producing high quality Hyperspectral images for the last 7 years. The requirements for MERIS originally led to the development at e2v of both back-thinning technology, to meet the spectral requirements, and the manufacture of devices with a graded antireflection coating, to fully optimize the QE at every spectral band. A number of other hyperspectral missions are being planned or in preparation. For example Sentinel 3 is to be an almost direct repeat of the MERIS instrument and will be followed by Sentinel 4 and 5. In the future as the technology matures it is likely that Hyperspectral missions will tend to use CMOS sensors rather than CCD. CMOS sensors have a number of potential advantages for Hyperspectral imaging and if these can be successfully exploited then enhanced performance would result. The design of a CMOS sensor is discussed that is targeted at Hyperspectral application to give fully optimized performance at all spectral bands.