Distress radiolocation method and system
First Claim
1. A system for locating a signal source transmitting a short duration signal from an unknown location within an area of coverage, said system comprising:
- receiving means at a plurality of known geographical locations for receiving the short duration signal, said receiving means including measuring means for developing a numerical representation of a magnitude of the received signal at each known location; and
calculating means for numerically calculating, from the numerical representations and the known locations, the geographical location of the signal source.
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0 Petitions
Accused Products
Abstract
A dedicated distress radiolocation system combines direction-finding techniques with calculations based on signal strength to precisely locate a distress transmission and effect rescue of the person or property in distress. The system is capable of locating a distress transmission solely on the basis of a short duration pulse; however, for identification purposes and for communication reliability a series of pulses is transmitted. The system includes distress transmitters, a plurality of slave repeater units at known locations to receive the distress transmission and report their signal strength to a central station, a central station to calculate the distress transmitter'"'"'s location based on the measured signal strengths and the known locations of the repeater units and to dispatch a rescue unit, and rescue units equipped with direction finding equipment to approach the distress transmitter. Most actions of the system are undertaken automatically.
373 Citations
25 Claims
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1. A system for locating a signal source transmitting a short duration signal from an unknown location within an area of coverage, said system comprising:
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receiving means at a plurality of known geographical locations for receiving the short duration signal, said receiving means including measuring means for developing a numerical representation of a magnitude of the received signal at each known location; and calculating means for numerically calculating, from the numerical representations and the known locations, the geographical location of the signal source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 13, 14)
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8. A distress radio location system for locating a radio transmitter transmitting a short duration radio signal from an unknown location within an area of coverage, said distress radio location system comprising:
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a plurality of radio receivers at known geographical locations to receive the short duration radio signal; signal strength measuring means coupled to each of said receivers for developing a numerical representation of a signal strength of the radio signal received at the known locations; and calculating means for numerically calculating, from the numerical representations and the known locations, the geographical location of the transmitter. - View Dependent Claims (9, 10, 11)
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12. A method of locating a signal source transmitting a short duration signal from an unknown location, said method comprising the steps of:
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developing a numerical representation of a magnitude of the short duration signal at each of a plurality of known geographical locations; and numerically calculating, from the numerical representations and the known locations, the geographical location of the signal source. - View Dependent Claims (15, 16, 17)
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18. A method of establishing a line of position to locate a signal source trnasmitting a target signal from an unknown location, said method comprising the steps of:
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transmitting a calibration signal from a predetermined position; developing a numerical representation of a magnitude of the calibration signal at a known location; determining a relationship between the numerical representation of the magnitude of the calibration signal, the predetermined position, and the known location; developing a numerical representation of the magnitude of the target signal at the known location; and numerically calculating, from the numerical representation of the magnitude of the target signal, the known location, and the relationship, a line of position locating the signal source.
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19. In a system for locating a signal source transmitting a signal from an unknown location, the system including as an old element calculating means receiving input information for numerically calculating the location of the signal source, a repeater unit comprising:
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receiver means for receiving the signal; measuring means coupled to said receiver means for developing a numerical representation of a magnitude of the signal; encoding means coupled to said measuring means for formatting the numerical representation and an identification of said repeater unit into a message; and transmitter means coupled to said encoding means for transmitting the message to the calculating means as the input information. - View Dependent Claims (20, 21, 22, 23)
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24. A system for locating a signal source transmitting a series of short duration signals from an unknown location, said system comprising:
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receiving means at a plurality of known locations for receiving at each known location a plurality of the short duration signals, said receiving means including measuring means for developing a numerical representation of a magnitude of each of the received signals at each known location; calculating means for numerically calculating, from the numerical representations and the known locations, the location of the signal source; and mobile means in communication with said calculating means for approaching the calculated location of the signal source, said mobile means including direction finding means for precisely locating the signal source.
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25. A distress radio location system for locating a radio transmitter transmitting a series of short duration radio signals from an unknown location, said distress radio location system comprising:
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a pluarality of radio receivers at known locations to receive at each known location a plurality of the short duration radio signals; signal strength measuring means coupled to each of said receivers for developing a numerical representation of a signal strength of each of the received radio signals at each known location; calculating means for numerically calculating, from the numerical representations and the known locations, the location of the transmitter; and mobile direction finding means in communication with said calculating means for approaching the calculated location of the transmitter.
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Specification