Resolution and sensitivity of superband sensors

With improvements and new developments in infrared optical system detector materials, superband imaging systems spanning the short-wave infrared (SWIR) through the midwave infrared (MWIR) are now possible. Previous works on these systems have yet to characterize the resolution and sensitivity of these systems compared with the constituent individual infrared bands. These system characteristics are extremely important for understanding the potential targeting benefits of an optical system. Thus, a Cyan Systems superband camera with the response from 1 to 5 μm was used to image various optical targets in four field tests—one in day and one at night for both a maritime and rural imaging environment. From the target images, the modulation transfer function, noise equivalent power, and contrast signal-to-noise ratio are measured for the superband system compared with a 1 to 1.9 μm filtered SWIR band, a 2 to 2.5 μm filtered extended SWIR band, and a 3 to 5 μm filtered MWIR band, all using the same superband camera. The results from the field tests are compared with a theoretical model using the night vision integrated performance model. In addition, three potential ideal superband imaging systems are presented, and targeting benefits for each system are discussed.