Real time imaging system and method for use in aiding a landing

Abstract

An imaging apparatus for aiding landing of aircraft in weather conditions obscuring a pilot's view of a runway. The apparatus comprises a plurality of LED assemblies which are disposed along the runway. Each LED assembly includes a plurality of LEDs, a receiver and a plurality of drivers responsive to the receiver for energizing the LEDs. The LEDs of each LED assembly are pulsed on by signals from a transmitter disposed adjacent an end of the runway. The transmitter also sends synchronization signals to a receiver located on board the approaching aircraft. The receiver on the aircraft is coupled to a processor which uses the synchronization signals to determine when the LEDs are energized and when they are not energized. The processor controls a CCD camera mounted on the aircraft so as to obtain an unobstructed view of the approaching runway. The processor controls the CCD camera such that the camera takes images (i.e., frames) while the LEDs are pulsed on and also while the LEDs are off. The frames with the LEDs off are then digitally subtracted from the frames taken while the LEDs were energized to produce enhanced images which are output to a visual display on-board the aircraft and which do not include the objectionable radiant background information. In an alternative embodiment a plurality of independent groups of LED assemblies are controlled in accordance with separate synchronization frequencies. The pilot is instructed which synchronization frequency to select, and only the LED assemblies corresponding to the selected group appear as being continuously illuminated on board the visual display on the aircraft.