AERIAL RECONNAISSANCE CAMERA SYSTEM WITH ATMOSPHERIC DISPERSION CORRECTION

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.