Abstract: A wide field of view monocentric lens system for an infrared aerial reconnaissance camera includes front and rear lens shell elements and a core lens element, with the number of front and rear shell lens elements depending on the IR band of interest (LWIR, MWIR or SWIR). Infrared radiation entering the monocentric lens passes sequentially through the front shell lens element(s), the core lens element, and the rear shell lens element(s) and is focused onto a curved focal surface. The front shell lens element(s) and the rear shell lens element(s) are made of material having a relatively higher refractive index or a relatively higher optical dispersion, or both, in the band of interest, as compared to the core lens element.

Abstract: An aerial reconnaissance camera system is disclosed which compensates for atmospheric dispersion. The dispersion is principally a function of the observing altitude and slant range and occurs in the camera depression direction only. The effective spectral dispersion of the atmosphere is shown to be about 15 microradians over the visible/near infrared spectrum (500 to 900 nanometers) at typical long range oblique photography (LOROP) imaging ranges. Consequently, dispersion is compensated by means of a fixed optical wedge incorporated into the optical path of the reconnaissance camera, e.g., in a fixed reconnaissance window. The wedge has dispersive qualities opposite to the effective net dispersion of the atmosphere for an expected reconnaissance mission using the camera.

Abstract: A wide field of view monocentric lens system for an infrared aerial reconnaissance camera includes front and rear lens shell elements and a core lens element, with the number of front and rear shell lens elements depending on the IR band of interest (LWIR, MWIR or SWIR). Infrared radiation entering the monocentric lens passes sequentially through the front shell lens element(s), the core lens element, and the rear shell lens element(s) and is focused onto a curved focal surface. The front shell lens element(s) and the rear shell lens element(s) are made of material having a relatively higher refractive index or a relatively higher optical dispersion, or both, in the band of interest, as compared to the core lens element.

Abstract: An aerial reconnaissance camera system is disclosed which compensates for atmospheric dispersion. The dispersion is principally a function of the observing altitude and slant range and occurs in the camera depression direction only. The effective spectral dispersion of the atmosphere is shown to be about 15 microradians over the visible/near infrared spectrum (500 to 900 nanometers) at typical long range oblique photography (LOROP) imaging ranges. Consequently, dispersion is compensated by means of a fixed optical wedge incorporated into the optical path of the reconnaissance camera, e.g., in a fixed reconnaissance window. The wedge has dispersive qualities opposite to the effective net dispersion of the atmosphere for an expected reconnaissance mission using the camera.