VEHICLE COMMAND AND CONTROL SYSTEM
First Claim
1. In combination:
- means for transmission of a substantially continuous wave signal of a first frequency from a first station at a first location;
at least one means at a second location for receiving said first frequency substantially continuous wave signal and for transmitting a signal at a second frequency;
a plurality of additional stations at other locations for receiving said first and second frequency signals and for generating a measurement indicative of the time difference between said first and second frequency signals; and
means for receiving said measurements from said plurality of additional stations for determining the position of said means at said second location.
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Abstract
A dual frequency ranging and communication system for communicating with and locating mobile vehicles in a multipath environment such as an urban center. This system functions in urban areas for both communication and ranging where line of sight radiation techniques may not properly function. A plurality of remote relay stations are located at points throughout the urban area, each station receiving and transmitting coded digital data and tone signals, the tone signals being used for phase ranging. Each of the vehicles is equipped with a transponder responsive only to the radio signal having a formatted message including the vehicle identification code with a ranging tone suitably impressed thereon. The formatted signal is transmitted from one of the relay stations at a first frequency and picked up by a preselected number of other relay stations as well as by the vehicle transponder. The vehicle transponder in turn generates a reply signal at a second frequency containing message data and a tone signal modulated on the second frequency for use in ranging, all of which signals are processed at a central location.
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Citations
23 Claims
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1. In combination:
- means for transmission of a substantially continuous wave signal of a first frequency from a first station at a first location;
at least one means at a second location for receiving said first frequency substantially continuous wave signal and for transmitting a signal at a second frequency;
a plurality of additional stations at other locations for receiving said first and second frequency signals and for generating a measurement indicative of the time difference between said first and second frequency signals; and
means for receiving said measurements from said plurality of additional stations for determining the position of said means at said second location.
- means for transmission of a substantially continuous wave signal of a first frequency from a first station at a first location;
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2. A combination in accordance with claim 1 wherein at least one of said receiving means includes a predetection signal combination network.
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3. A combination in accordance with claim 1 wherein at least one of said receiving means includes a postdetection signal combination network.
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4. In combination:
- means for transmission of a substantially continuous wave signal of a first frequency from a first station at a first location, at least one means at a second location for receiving said first frequency signal and for transmitting a substantially continuous wave signal at a second frequency in response thereto;
a plurality of additional stations at other locations for receiving said first and second frequency signals and for generating a phase measurement therefrom; and
computing means for receiving said phase measurements from said plurality of additional stations for determining the position of said transponder.
- means for transmission of a substantially continuous wave signal of a first frequency from a first station at a first location, at least one means at a second location for receiving said first frequency signal and for transmitting a substantially continuous wave signal at a second frequency in response thereto;
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5. A combination in accordance with claim 4 wherein said second frequency signal is received at said first station and means at said first station for generating a phase measurement from said first and second frequency signals which is supplied to said computing means with the phase measurements from said plurality of additional stations for determining the position of said transponder.
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6. In combination:
- means for transmission of a signal carrier of a first frequency from a first station at a first location;
means for frequency modulating said carrier at a predetermined modulation frequency;
at least one transponder means at a second location for receiving said first frequency signal and for transmitting a signal at a second frequency in response thereto;
means at said second location for frequency modulating said first frequency signal at the same modulation frequency as said first frequency signal is modulated;
a plurality of additional stations at other locations for receiving said first and second frequency carrier signals with said modulation frequency modulated thereon and for generating a phase measurement between the two received modulation signals; and
computing means for receiving the phase measurement from said plurality of additional stations for determining the position of said transponder.
- means for transmission of a signal carrier of a first frequency from a first station at a first location;
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7. A combination in accordance with claim 6 in which f1 and f2 are in the UHF region.
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8. A phase ranging system comprising a master station, a plurality of phase stations, first transmission means at said master station for transmitting a modulated substantially continuous wave signal at a first frequency, transponder means at at least one mobile vehicle for receiving said frequency signal and for transmitting a modulated substantially continuous wave signal at a second frequency in response thereto, means at said master station and at said slave stations for receiving said first and second frequency modulated signals;
- means at said master station and at said slave stations for phase comparing the modulation on said first frequency and on said second frequency to obtain a plurality of distance measurements of the vehicle from the respective master and slave stations; and
means for transmitting the plurality of phase measurements to a central computing means for determining the position of said mobile vehicle.
- means at said master station and at said slave stations for phase comparing the modulation on said first frequency and on said second frequency to obtain a plurality of distance measurements of the vehicle from the respective master and slave stations; and
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9. A phase ranging system comprising a master station, a plurality of phase stations, first transmission means at said master station for transmitting a modulated signal at a first frequency, transponder means at at least one mobile vehicle for receiving said first frequency signal and for transmitting a modulated signal at a second frequency in response thereto, means at said master station and at said slave stations for receiving said first and second frequency modulated signals;
- means at said master station and at said slave stations for phase comparing the modulation on said first frequency and on said second frequency to obtain a plurality of distance measurements of the vehicle from the respective master and slave stations;
means for transmitting the plurality of phase measurements to a central computing means for determining the position of said mobile vehicle; and
said means for transmission of said phase measurements to said central control means comprisinG telephone lines.
- means at said master station and at said slave stations for phase comparing the modulation on said first frequency and on said second frequency to obtain a plurality of distance measurements of the vehicle from the respective master and slave stations;
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10. In combination, a ranging and communication system comprising:
- a central processor;
a plurality of remote relay stations;
at least one vehicle equipped with a transponder;
means at at least one of said remote relay stations for transmitting an omnidirectional signal having coded indicia and a ranging signal modulated thereon;
means at said transponder responsive only to said coded indicia for generating a coded reply signal including a ranging signal within a predetermined time after receipt of said transmitted signal;
receiving means at each of said plurality of remote relay stations for detecting and decoding said signal transmitted from said transponder and said omnidirectional signal;
means at each of said plurality of remote relay stations for generating a measurement indicative of the time difference between the transmission from said relay station and the transmission from said transponder;
means for transmitting said detected and decoded signals from said plurality of relay stations to the central processor.
- a central processor;
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11. A combination phase ranging and communication system in accordance with claim 10 wherein said omnidirectional signal transmitted from at least one relay station includes a carrier at a first frequency with a range tone modulated thereon and said transponder signal from said vehicle generated in response to the receipt of said omnidirectional signal comprises a carrier at a second frequency with a ranging tone modulated thereon.
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12. A combination phase ranging and communication system in accordance with claim 11 wherein the portion of said first and said second modulated signals containing the range tone modulated on said respective first and second frequency signals is transmitted simultaneously from said remote relay station and from said vehicle.
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13. A combination phase ranging and communication system in accordance with claim 11 wherein said omnidirectional signal additionally contains a vehicle identification code modulated thereon such that only the transponder on the particular vehicle for which said identity code is intended will transpond in response to said omnidirectional signal.
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14. A combination phase ranging and communication system in accordance with claim 13 wherein said second frequency signal containing the range tone modulated thereon is transmitted simultaneously with said first omnidirectional signal having said range tone modulated thereon.
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15. A combination phase ranging and communication system in accordance with claim 13 further comprising phase measuring means at each of said remote relay stations for measuring the phase difference between the ranging tones modulated on said first and second frequency signals to derive positional information as to the location of said vehicle;
- and means for transmission of said plurality of phase measurements to said central processor for computation of the vehicle location.
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16. A combination phase ranging and communication system in accordance with claim 15 wherein said means for transmission of said phase information from the plurality of relay stations to the central processor is a plurality of telephone data channels and further including a telephone data channel for transmission of control signals from the central processor to said remote relay station transmitting said omnidirectional signal. 17 A combination phase ranging and communication system in accordance with claim 16 wherein said central processor comprises a digital computer.
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18. A phase ranging system for command and control of a fleet of mobile vehicles in a high multipath signal clutter environment such as a city comprising:
- a plurality of remote relay stations for transmission of an omnidirectional frequency modulated substantially continuous wave carrier of a first frequency;
a plurality of transponders located at different vehicles;
each of said transponders being operable upon receipt of said first frequency signal for acTivating means for transmitting a frequency modulated substantially continuous wave carrier at a second frequency; and
means at said plurality of remote relay stations for receiving said first and second frequency modulated signals and for deriving a phase measurement therefrom indicative of the location of said transponders.
- a plurality of remote relay stations for transmission of an omnidirectional frequency modulated substantially continuous wave carrier of a first frequency;
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19. A phase ranging system for command and control of a fleet of mobile vehicles in a high multipath signal environment such as a city in accordance with claim 18 further including diversity reception means for diversity reception of said transponded signals, including two receivers for receiving said second frequency signal;
- and a predetection combiner fed with the detected modulation on said second frequency signal from both of said receivers.
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20. A phase ranging system for command and control of a fleet of mobile vehicles in a high multipath signal clutter environment such as a city comprising:
- a plurality of remote relay stations for transmission of an omnidirectional frequency modulated carrier of a first frequency;
a plurality of transponders located at different vehicles;
each of said transponders being operable upon receipt of said first frequency signal for activating means for transmitting a frequency modulated carrier at a second frequency;
means at said plurality of remote relay stations for receiving said first and second frequency modulated signals and for deriving a phase measurement therefrom indicative of the location of said transponders; and
said frequency modulated carrier transmitted from said plurality of remote relay stations having modulated thereon a formatted message having a synchronization portion, a vehicle code identification portion, a coded data portion, and a ranging signal such that only the particular vehicle transponder containing a corresponding vehicle identification code will transpond in response to said transmission.
- a plurality of remote relay stations for transmission of an omnidirectional frequency modulated carrier of a first frequency;
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21. A system in accordance with claim 20 in which said formatted message is a digital code modulated onto said carrier.
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22. A system in accordance with claim 21 in which said second frequency modulated carrier transmitted from said transponder contains a coded digital message and a ranging tone modulated thereon is transmitted simultaneously with the transmission of the portion of said formatted message modulated on said first frequency carrier that contains the digitally coded message and the ranging tone from said relay station.
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23. A phase ranging system in accordance with claim 22 wherein said vehicle code identification portion of said first frequency signal keys on the transponder responsive to that particular vehicle identity code to transpond simultaneously with the remainder of the message at said first frequency, said transponder frequency being at said second frequency.
Specification