A GFCR system receives light from a scene of interest and focuses it to form an image. Light associated with a selected field-of-view of the image is confined to a spectral band absorbable by a gas of interest and is split into first and second paths. A region that does not substanti
An entrance aperture of a GFCR system receives light from a scene of interest. The light is focused to form an image at a focal plane. Light associated with a selected field-of-view of the image at the focal plane is then confined to a spectral band at which a gas of interest absorbs.
An atmospheric refraction profile is determined using an imaging system positioned at a location that is simultaneously within line-of-sight of two celestial light sources. A variety of active or passive methods can be employed to cause the line-of-sight to vertically traverse through a
A method is presented for calibrating an infrared sensing device while in an orbit above a celestial body. The infrared sensing device measures a signal profile proportional to radiance emission from the atmospheric limb region in each of a plurality of spectral bandpass regions. The rad
