Fuze system that utilizes a reflected GPS signal
AssigneeFIRST RF Corporation
InventorBenjamin R. Wilmhoff
Life of this patent
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Abstract
The present invention is directed to fuze system for munition that produces a height-of-burst (HOB) signal using two Global Positioning System (GPS) signals, the first signal being from a particular GPS satellite (the direct GPS signal) and the second signal being the GPS signal from the same GPS satellite after the signal has been reflected from the surface adjacent to the target. In one embodiment, the HOB signal is generated when there is a substantial correlation between the reflected GPS signal and direct GPS delayed by an amount of time that is indicative of the desired HOB.
Claims18
A munition with a passive height-of-burst (HOB) fuze system comprising:
- a munition;
- a HOB system, operatively attached to the munition, for producing a HOB signal for the munition at a desired HOB, the system comprising:
- GPS signal acquisition and demodulation circuitry for acquiring direct and reflected GPS signals for a particular GPS satellite and demodulating the direct and reflected GPS signals to respectively produce a direct pseudo-random code and a reflected pseudo-random code;
- correlation circuitry for producing a correlation signal indicative of the correlation between the direct pseudo-random code delayed by a period of time related to the desired HOB and the reflected pseudo-random code;
- and
- HOB detection circuitry for processing the correlation signal to determine when the munition is at or near a desired HOB and, if at or near the desired height, produce an HOB signal.
A height-of-burst (HOB) fuze system for use with a munition, the system comprising:
- GPS signal acquisition and demodulation circuitry for acquiring a direct signal and reflected GPS signals for a particular GPS satellite and demodulating the direct and reflected GPS signal to respectively produce a direct pseudo-random code and a reflected pseudo-random code;
- correlation circuitry for producing a correlation signal indicative of the correlation between the direct pseudo-random code delayed by a period of time related to the desired HOB and the reflected pseudo-random code;
- and
- HOB detection circuitry for processing the correlation signal to determine when the munition is at or near a desired HOB and, if at or near the desired height, produce an HOB signal.
A method for determining when a munition is at a desired height-of-burst comprising:
- providing a munition;
- receiving, at the munition, a direct GPS signal from a satellite;
- receiving, at the munition, a reflected GPS signal from the satellite;
- delaying the direct GPS signal by a time delay that is representative of the desired height-of-burst to produce a delayed GPS signal;
- assessing the correlation of the reflected GPS signal and the direct GPS signal delayed by the time delay;
- and
- providing, at the munition, a HOB signal if there is a high degree of correlation between the reflected GPS signal and the direct GPS signal delayed by the time delay.
Dependencies are inferred from the claim text.