Patent ID: 7641153
Filing Date: 2010-01-05
Classification: B64C

Abstract:
1. A method of reducing noise generated by a shockwave created from an airborne mobile platform travelling at a supersonic speed above the Earth's surface, the mobile platform having a length, and the method comprising: directing laser electromagnetic radiation in a direction forwardly of the mobile platform and offset from a longitudinal centerline of the mobile platform, and to a predetermined location at least about one mobile platform length forwardly and offset from the longitudinal centerline of the mobile platform, the laser electromagnetic radiation being to a first volume of a gas whereby the laser electromagnetic radiation causes the first volume of the gas to become ionized; directing microwave electromagnetic radiation in the same direction as the laser electromagnetic radiation and to the predetermined location, to a second volume of the gas, where the second volume of gas forms a sphere that envelopes the first volume of gas and is larger than the first volume of gas by a factor of at least about 1000, the microwave electromagnetic radiation causing the second volume of the gas to become ionized and heated; and the second volume of the gas being located such that the second volume of the gas is overrun by a shockwave generated forwardly of the moving mobile platform, relative to its direction of travel, and such that coalescing of components of the shockwave in a far field area at least about ten mobile platform lengths from the mobile platform is inhibited, to weaken the shockwave produced at the Earth's surface.