Aircraft defense system against manpads with IR/UV seekers
An inexpensive, efficient and lightweight integrated small decoy system towed behind an aircraft to power an intense IR emitter for drawing in a missile with an IR sensitive guidance system away from vulnerable parts of a defended aircraft is combined with a system for simultaneously cloaking the aircraft with spectral bands of atmospherically scattered UV solar radiation reflected, and radiated from UV radiant sources mounted on the aircraft to defend against advanced MANPADS missiles with guidance systems sensitive to UV shadows cast by an aircraft in a background sky radiance of atmospherically scattered solar UV. Both the reflected and direct cloaking UV emittance may be spatially and/or temporally modulated to confuse an incoming missile. The UV aspect of this invention may also be combined with other C-MANPADS missiles, such as DIRCM, to provide additional defensive capability.
1. A method for cloaking an aircraft flying during daytime through the atmosphere, the steps comprising:
a) locating electromagnetic radiation sources at various positions on exterior surfaces of an aircraft structure that radiate in at least one particular spectral band of solar radiation scattered in the atmosphere;
b) treating the exterior surfaces of the aircraft structure to reflect electromagnetic radiation at the particular spectral bands radiated by the radiation sources;
c) irradiating selected exterior surfaces of the aircraft with radiation from the variously located electromagnetic radiation sources during selected portions of a flight of the aircraft.
2. The method of claim 1 wherein the treatment is coating.
3. The method of claim 2 wherein the coating treatment is paint.
4. The method of claim 1 wherein the variously located radiation sources radiate in particular UVA radiation spectral bands having wavelengths ranging between 300 nm and 400 nm that are scattered in the atmosphere.
5. The method of claim 1 wherein the variously located radiation sources radiate in the particular spectral bands with sufficient radiant flux for inducing radiance from the selected irradiated exterior surfaces of the aircraft comparable to sky background radiance in the particular spectral bands, whereby, the selected irradiated surfaces are sensed as having a radiance essentially equivalent to sky background radiance in those particular spectral bands.
6. The method of claim 1 and further including steps of:
d) locating arrays of radiation sources at selected locations on the aircraft structure that are occluded in part, by structural features of the aircraft flying at usual attitudes from direct irradiation by sky background radiation for radiating outward from the aircraft and for irradiating surrounding surfaces of the aircraft structure in particular spectral bands of solar radiation scattered in the atmosphere; and
e) energizing selected arrays of radiation sources to radiate during selected portions of a flight of the aircraft.
7. The method of claim 6 wherein the selected, energized arrays of radiating radiation sources provide an average radiance from the selected locations on the aircraft structure at least comparable to anticipated radiance of daytime background sky radiation in the particular spectral bands.
8. A method for cloaking an aircraft flying during daytime through the atmosphere, the steps comprising:
a) locating arrays of electromagnetic radiation sources at selected locations on the exterior of an aircraft structure for radiating from the aircraft and irradiating surrounding surfaces of the aircraft structure in at least one spectral band of sky background radiation that are occluded in part by structural features of the aircraft flying at usual attitudes from direct irradiation by sky background radiation;
b) treating exterior surface regions of the aircraft structure to enhance reflection of radiation in the particular spectral bands radiated by the radiation sources;
c) energizing selected arrays of radiation sources for radiating electromagnetic energy in the particular spectral bands outward from the aircraft and for irradiating surrounding treated exterior surface regions of the aircraft structure for reflecting that radiation during selected portions of a flight of the aircraft.
9. The method of claim 8 wherein selected arrays of radiation sources radiate electromagnetic radiation having a radiance at least comparable to anticipated daytime sky background radiation radiance in the particular spectral bands.
10. The method of claim 8 wherein selected arrays of radiation sources radiate in particular UVA solar spectral bands having wavelengths ranging between 400 nm and 300 nm scattered by the atmosphere.
11. The method of claim 1 or 8 and further including the step of providing the aircraft with a defensive system against heat-seeking missiles.
12. The method of claim 11 wherein the defensive system is a towed IR-emitting decoy.
13. The method of claim 11 wherein the defensive system is a directed infrared laser.
14. The method of claim 11 wherein the defensive system comprises flares.
15. The method of claim 12 wherein the decoy is self-powered.
16. The method of claim 11 wherein the variously located radiation sources are energized to radiate in the particular spectral bands and the defensive system against heat-seeking missiles is deployed during takeoff and landing approach phases during a flight the flying aircraft.
17. The method of claim 1 or 8 and further including the step of:
(i) modulating the intensities of the radiation emitted by selected arrays of electromagnetic radiation sources during selected portions of a flight of the aircraft.