FILTER INCIDENCE NARROW-BAND INFRARED SPECTROMETER

A system and methods for optically detecting a target atmospheric gas are disclosed and described. An imaging system can include a narrow-band optical interference filter with a center wavelength that corresponds to a feature in an absorption spectrum of a target gas at a normal angle of incidence. An optical component can receive incoming light from the target gas that has passed through the narrow-band optical interference filter, wherein the narrow-band optical interference filter is tilted relative to the optical component, which tilt shifts the wavelength of light from each target point that is able to pass through the narrow-band optical interference filter. A camera can receive the incoming light that has been focused by the optical component. Multiple image frames are collected for different orientations of the system with respect to the target and analyzed to perform hyperspectral characterization of target gas absorption.