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MICROWAVE FLAW DETECTOR

NASA Case No. ARC-10009

Canada

Address inquiries to:
Ames Research Center
Attn: Patent Counsel
Mail Code: 200-11A
Moffett Field, CA 94035
U.S.A.

[Corresponding to U.S. Patent No. 3,532,973]

The basic theory of a microwave metal surface flaw detector is that irradiation of a flawed metal surface by electromagnetic microwave energy results in re-emission of electromagnetic energy from the surface in a pattern of eigenmodes different from those of the original irradiating signal. The incident microwave signal must satisfy the electromagnetic boundary conditions on the surface of the specimen. In accordance with the present invention, there is provided a flaw detection system utilizing microwave energy which is radiated to the test surface and which varies in a cyclic or return-to-zero manner. The test surface modifies the reflected electromagnetic energy, in accordance with the surface condition, so that the reflected energy provides a measure of the surface condition as a function of the cyclic scan angle. This reflected energy is demodulated and then correlated, either with itself or with a reference pattern, to provide an indication of irregularities in the surface.

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Fire resistant coating compositions intended for high temperature applications, which when dried are flake, crack, craze, and abrasion resistant and of greatly reduced leachability. The compositions, which are combinable with selected conventional pigments and fillers, comprise a combination of a potassium silicate solution, ceric oxide, and/or alkyl trialkoxy silane as rehydration suppressants, and wollastonite as a film builder.

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[Corresponding to U.S. Patent No. 3,534,367]

System and method for position locating, deriving centralized air traffic control, data, and communicating via voice and digital signals between a multiplicity of remote aircraft (including supersonic transports) and a central station, as well as a peripheral ground station(s), through a synchronous satellite relay station. Side tone ranging patterns, as well as digital and voice signals are modulated on a carrier transmitted from the central station and received on all of the supersonic transports. Each aircraft communicates with the ground stations via a different frequency multiplexed spectrum. Supersonic transport position is derived from a computer at the central station and supplied to a local air traffic controller. Position is determined in response to variable phase information imposed on the side tones at the aircraft, and relayed back to the transports. Common to all of the side tone techniques is Doppler compensation for the supersonic transport velocity.

The patent coverage of GSC-10087-1 is directed to transmitting a first side tone spectrum from a first point, transmitting a carrier modulating with a second side tone spectrum frorn a second point, receiving the first and second spectrums on an aircraft, determining from the phase of the tones the distance of the aircraft relative with the first and second points, determining the distance of the aircraft from the center of the Earth, and then combining the three distances to establish the location of the aircraft.

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POSITION LOCATION SYSTEM AND METHOD

NASA Case No. GSC-10087-2

Belgium, Canada, France,
Great Britain, Switzerland,
West Germany

Address inquiries to:
Goddard Space Flight Center

Attn: Patent Counsel
Mail Code: 204

Greenbelt, MD 20771
U.S.A.

[Corresponding to U.S. Patent No. 3,495,260]

System and method for position locating, deriving centralized air traffic control data, and communicating via voice and digital signals between a multiplicity of remote aircraft (including supersonic transports) and a central station, as well as a peripheral ground station(s), through a synchronous satellite relay station. Side tone ranging patterns, as well as digital and voice signals are modulated on a carrier transmitted from the central station and received on all of the supersonic transports. Each aircraft communicates with the ground stations via a different frequency multiplexed spectrum. Supersonic transport position is derived from a computer at the central station and supplied to a local air traffic controller. Position is determined in response to variable phase information imposed on the side tones at the aircraft, and relayed back to the transports. Common to all of the side tone techniques is Doppler compensation for the supersonic transport velocity.

The claim coverage of GSC-10087-2 varies in at least one respect in that the Doppler frequency shift on the carrier is utilized to provide a determination of the velocity of the object relative to a satellite station.

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This invention is a replacement for strain gages and accelerometers. The device may be used in any environment where conventional piezoresistive or strain gage electromechanical transducers can be used. In addition to the foregoing uses, the device can be used in bioelectric sensing due to its small size. The transducer, of anisotropic piezoresistive material, includes a body of semiconductor material having a longitudinal force axis that is skewed with respect to the crystallographic orientation of the body. The material combines the pinch effect with the piezoresistive effect. The device produces a much larger electrical signal for a given stress than presently known in the prior art.

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