THALES have developed for volume manufacture two high performance low cost thermal imaging cameras based on the THALES Research & Technology (TRT) 3rd generation gallium arsenide long wave Quantum Well Infrared Photodetector (QWIP) array. Catherine XP provides 768 x 575 CCIR video resolution and Catherine MP provides 1280 x 1024 SXGA video resolution. These compact and rugged cameras provide 24-hour passive observation, detection, recognition, and identification in the 8 to 12μm range, providing resistance to battlefield obscurants and solar dazzle, and are fully self-contained with standard power and communication interfaces. The cameras have expansion capabilities to extend functionality (for example automatic target detection) and have network battlefield capability. Both cameras benefit from the high quantum efficiency and freedom from low frequency noise of the TRT QWIP, allowing operation at 75 K, low integration times and non-interruptive non-uniformity correction. The cameras have successfully reached
technology readiness level 6/7 and have commenced environmental qualification testing in order to complete the development programmes. These latest additions to the THALES Catherine family provide high performance thermal imaging at an affordable cost.
Successful past experience of implementing long wave MCT 1st and 2nd Generation thermal imagers has demonstrated to THALES Optronics that MCT presents difficult challenges when correcting non-uniformity errors caused by rapidly changing detector element gain and offset drifts. These problems become even more demanding when the move is made from long linear arrays to focal plane arrays due to the significantly larger number of detector elements. Relaxation of these demands would make a significant impact on the price/performance trade which inevitably occurs in a camera development. In recognition of the need to offer UK MOD best value, THALES Optronics has initiated a programme to achieve a SXGA resolution camera and is working with UK MOD, over a two year period, to investigate whether an alternative technology can maintain the high resolution required whilst achieving a downward step change in price. The selected technology is 3rd Generation Gallium Arsenide long wave Quantum Well Infra-red Photodiode (QWIP) chosen because initial indications are that drift rates are orders of magnitude slower than MCT. The programme involves studies to determine effects of defect clusters, bimodalism, non-uniformity correction levels and higher than normal operating temperatures on achieving acceptable performance, including logistics, in user scenarios whilst maximising detector yield. Development of demonstrator IR camera hardware (technology readiness level 6/7) based on a THALES Research & Technology QWIP array is also part of the programme.