Patent ID: 7705879

Claim:
A method of using an aircraft-borne system to accomplish early acquisition of landing zone illumination obscured from pilot view because of visible light extinguishing atmospheric conditions, comprising: modulating the landing zone illumination at a modulation rate; using an imaging camera to acquire a sequence of image frames of a scene in which the landing zone illumination is contained, the sequence of image frames being acquired at a rate that is synchronized with and is a known multiple of the modulation rate; setting the known multiple to a value that causes the sequence of image frames to include first and second sets of images representing, respectively, background scene information including the landing zone illumination and background scene information not including the landing zone illumination; and processing the first and second sets of images to remove the background scene information from temporally corresponding images of the first and second sets and thereby provide processed image information from which acquisition of the landing zone illumination can be performed.