US Patent 7642929 Helicopter brown-out landing

An electromagnetic emissions free optical signal based helicopter landing assistance arrangement wherein helicopter rotor wash dust cloud-caused obfuscation of the intended landing site and other landing threats are overcome. Real time optical sourced data is collected early and used during helicopter approach to the intended landing site. Upgrading of this data for use during dust cloud presence is accomplished with image processing techniques applied in response to such inputs as helicopter flight data. Military use of the invention especially in current theatre conflict environments is contemplated. Dust cloud related landing hazards are disclosed as a significant difficulty in such environments and generate need for the invention.