Abstract : The Adaptive Infrared Imaging Sectroradiometer (AIRIS) is a hyperspectral imaging system comprising a low order tunable Fabry Perot etalon coupled to an IR focal plane array. A MWIR AIRIS system utilizing an InSb focal plane was developed by Physical Sciences Inc. (PSI) under the sponsorship of the Armament Division, Air Force Wright Laboratories for high-speed multispectral imagery of countermeasures and missile systems. In this paper we discuss: (1) the underlying concepts which form the basis of the AIR S sensor, (2) implementations of the concept and methods for optimizing system performance, (3) laboratory and limited field data gathered by MWIR variant of the sensor, and (4) preliminary data from an LWIR system under development. A key feature of the AIRIS approach is the ability to rapidly image the scene at only those wavelengths needed for identification and clutter suppression. This capability reduces the data rate, data volume, and processing requirements needed to effectively employ hyperspectral imagery for these applications.