Holistic approach to high-performance long-wave infrared system design

In past performance analyses and comparisons of midwave infrared (MWIR) and long-wave infrared (LWIR) systems, infrared systems scientists and engineers have not had the cumulative technologies that we will soon enjoy. Large format, small pitch, deep wells, and digital processing do not exist in a single focal plane, but they are a reality now individually and will exist collectively in the near future. How do we best use these technologies, and how do we compare sensors when we use these technologies? From a more fundamental aspect, how do you optimize a system given that practical limits are minimized and theoretical limits apply? Smaller pitch infrared detectors can provide longer range performance for a given aperture and higher photon collection duty cycles (deep wells and faster frame rates) can allow better modulation transfer function correction. Digital image processing allows for recovery of resolution by trading surplus signal-to-noise ratio. Nonuniformity correction becomes an important issue, but there are methods using higher duty cycles to address the problems. LWIR can compete with MWIR using the additional photons given an improved photon collection duty cycle. A holistic approach to system design can provide for an extremely high-performance system. It is also worth mentioning that infrared targeting sensor design in the future shall be quantified with more than just identification range. Since these technologies provide more than a human can consume, the sensors need to be designed to better utilize human consumption limits. An example is that small pitch high-density sensors (solid-state imaging) can provide faster target prosecution, which allows for faster target engagements. We show these possibilities using an LWIR targeting sensor to demonstrate the concept of optimizing pitch-well-processing.