Abstract: A multi-spectral imaging system utilizing tunable optics is disclosed. Various disclosed systems include a tunable optical filter coupled to a broadband imaging system. The tunable optical filter allows discrete infrared wavelengths to pass to the broadband imaging system so that monochromatic infrared images of a scene may be captured. An image processing system may process selected monochromatic infrared images by using a ratio technique to generate an emissivity-independent thermal image of the scene. The tunable optical filter may also be used to adjust a quality factor and control an amount of radiated energy that is passed to an image sensor of the broadband imaging system thereby acting as an aperture to account for both low and high radiance portions of the scene.

Abstract: A multi-spectral imaging system utilizing tunable optics is disclosed. Various disclosed systems include a tunable optical filter coupled to a broadband imaging system. The tunable optical filter allows discrete infrared wavelengths to pass to the broadband imaging system so that monochromatic infrared images of a scene may be captured. An image processing system may process selected monochromatic infrared images by using a ratio technique to generate an emissivity-independent thermal image of the scene. The tunable optical filter may also be used to adjust a quality factor and control an amount of radiated energy that is passed to an image sensor of the broadband imaging system thereby acting as an aperture to account for both low and high radiance portions of the scene.

Abstract: A device has been developed which monitors the presence of a flame within a combustion chamber. The optical flameout detection system responds to gross changes in combustor light intensity, which is monitored in two spectral bands. A photomultiplier tube makes optical measurements in the ultraviolet portion of the spectrum, and a silicon photodiode covers the visible region. The detectors, located outside the combustion chamber, receive the light energy radiated from the combustion process through fiber optic probes designed to operate in a high pressure environment. The optical fibers are aimed diagonally through the center of the injector at the combustion chamber wall downstream of the injector. The probed observe events occurring within a narrow conical-shaped field of view so that the system can quickly detect longitudinal movement of the flame front away from the injector.