Methods and apparatus for precise positioning of locations

Claim 2

A radio navigation system for determining the location of a station, comprising a first transmitter station fixedly disposed at a first location for generating a first preselected frequency; a second transmitter station fixedly disposed at a second location for generating a second preselected frequency; a reference transceiver fixedly disposed at a third different location for receiving said first and second frequencies, and including a precision frequency standard, said transceiver developing first and second error correction signals with respect to the signals of said frequency standard; and a receiver located at the station for receiving said first and second frequencies and said error correction signals, and including a precision frequency standard operating at a known relation to said frequency standard of said reference transceiver, for determining the position of said receiver with respect to said first and second transmitter stations, said error correction signals correcting for operational deviations of said station receiver precision frequency standards from said first and second preselected frequencies.

Claim 3

A radio navigation system for determining the location of a station, comprising a first transmitter station fixedly disposed at a first location for generating a first preselected frequency; a second transmitter station fixedly disposed at a second location for generating a second preselected frequency; a reference transceiver fixedly disposed at a third different location for receiving said first and second frequencies, and including a precision frequency standard, said transceiver developing first and second error correction signals with respect to the signals of said frequency standard; and a receiver located at the station for receiving said first and second frequencies and said error correction signals, and including a precision frequency standard operating at a known relation to said frequency standard of said reference transceiver, for determining the position of said receiver with respect to said first and second transmitter stations, said error correction signals correcting for operational deviations of said station receiver precision frequency standards from said first and second preselected frequencies.

Claim 4

A radio navigation system for determining the location of a station, comprising a first transmitter station fixedly disposed at a first location for generating a first preselected frequency; a second transmitter station fixedly disposed at a second location for generating a second preselected frequency; a reference transceiver fixedly disposed at a third different location for receiving said first and second frequencies, and including a precision frequency standard, said transceiver developing first and second error correction signals with respect to the signals of said frequency standard; and a receiver located at the station for receiving said first and second frequencies and said error correction signals, and including a precision frequency standard operating at a known relation to said frequency standard of said reference transceiver, for determining the position of said receiver with respect to said first and second transmitter stations, said error correction signals correcting for operational deviations of said station receiver precision frequency standards from said first and second preselected frequencies.

Claim 5

The system described in claim 1, wherein said first and second frequencies occupy a single frequency channel.

Claim 6

The system described in claim 2, wherein said first and second frequencies are both sums of coherent frequencies.

Claim 7

The system described in claim 3, wherein said reference transceiver and station receiver precision frequency standards generate synchronized and equal output frequencies.

Claim 8

The system described in claim 4, wherein said reference transceiver and station receiver each include a divider chain having a plurality of stages responsive to the output frequency of the frequency standard associated therewith and each delivering a fraction of said output frequency within a time period within which the other of said stages do not deliver any of said output frequencies, and combining means responsive to said divider chain for combining delivered fractions of said associated frequency standard into a preselected frequency for phase comparison with said preselected freqUencies from said first and second transmitter stations.

Claim 9

The receiver station described in claim 5, wherein said combining means further generates a fixed frequency difference relative to said selected one of said partial frequencies generated by said first and second transmitter stations.

Claim 10

The system described in claim 6, wherein the respective initial frequency of the preceding stage in each of said divider chains is divided by a factor of two in each of the subsequent stages therein.

Claim 11

The system described in claim 1, wherein said reference transceiver and station receiver precision frequency standards comprise atomic clocks.

Claim 12

The system described in claim 1, wherein said station is a mobile receiver station.

Claim 13

A radio navigation system as set forth in claim 1, wherein said reference transceiver includes a synthesizer for internally generating a first reference signal at approximately said first preselected frequency and a second reference signal at approximately said second preselected frequency, and comparison means for selecting and comparing said synthesized reference signals with said preselected frequencies for creating said error correction signals; and wherein said receiver station includes a synthesizer synchronized with said transceiver for internally generating a first signal at approximately said first preselected frequences and a second signal at approximately said second preselected frequency, and comparing means for selecting and comparing said signals synthesized in said station receiver with said preselected frequencies for determining position of said receiver, said error correction signals correcting for deviation said station receiver synthesizer fails to approximate said first and second frequencies.

Claim 14

A radio navigation system for determining the location of a station, comprising a first transmitter station fixedly disposed at a first location and generating a first identifiable signal of a preselected frequency, a second transmitter station fixedly disposed at a second location for generating a second identifiable signal of a preselected frequency, a reference transceiver fixedly disposed at a third different location for receiving said first and second identifiable signals and including a precision frequency standard, said transceiver developing first and second error correction signals of said preselected frequency with respect to the signal of said frequencies standard, and a receiver located at the station for receiving said first and second identifiable signals and said error correction signals, and including a precision frequency standard operating at a known relation to said frequency standard in said reference transceiver, for determining the position of said receiver with respect to said first and second transmitter stations, said error correction signals correcting for operational deviation of said station receiver precision frequency standard with respect to said preselected frequency.

Claim 15

A radio navigation system for determining the location of a station, comprising a first transmitter station fixedly disposed at a first location and generating a first identifiable signal of a preselected frequency, a second transmitter station fixedly disposed at a second location for generating a second identifiable signal of a preselected frequency, a reference transceiver fixedly disposed at a third different location for receiving said first and second identifiable signals and including a precision frequency standard, said transceiver developing first and second error correction signals of said preselected frequency with respect to the signal of said frequencies standard, and a receiver located at the station for receiving said first and second identifiable signals and said error correction signals, and including a precision frequency standard operating at a known relation to said frequency standard in said reference transceiver, for determining the position of said receiver with respect to said first and second transmitter stations, said error correction signals correcting for operational deviation of said station receiver precision frequency standard with respect to said preselected frequency.

Claim 16

A radio navigation system for determining the location of a mobile station, comprising a pair of transmitter stations at different fixed locations operating at respective carrier frequencies, a transceiver at a third fixed location, including a first precision frequency standard, and means for developing a digital error signal between said frequency standard and said received carrier frequencies, and a mobile receiver including a second precision frequency standard synchronized with said first frequency standard, and means for developing traveltime information from said received respective carrier frequencies and transmitting said traveltime information to said transmitter stations controlled by said second precision frequency standard, said means utilizing said digital error signal for improving said traveltime information.

Claim 17

A radio navigation system for determining the location of a mobile station, comprising a pair of transmitter stations at different fixed locations operating at respective carrier frequencies, a transceiver at a third fixed location, including a first precision frequency standard, and means for developing a digital error signal between said frequency standard and said received carrier frequencies, and a mobile receiver including a second precision frequency standard synchronized with said first frequency standard, and means for developing traveltime information from said received respective carrier frequencies and transmitting said traveltime information to said transmitter stations controlled by said second precision frequency standard, said means utilizing said digital error signal for improving said traveltime information.

Claim 18

The system described in claim 12, wherein said first and second precision frequency standards aRe essentially identical.

Claim 19

A radio navigation system for determining the location of a mobile station, comprising a pair of transmitter stations at different fixed locations operating at respective carrier frequencies, a transceiver at a third fixed location, including a first precision frequency standard, and means for developing an error signal between said frequency standard and said received carrier frequency, and a mobile receiver including a second precision frequency standard synchronized with said first frequency standard, means for developing traveltime information from said received respective carrier frequencies and transmitting said traveltime information to said transmitter station controlled by said second precision frequency standard, a unilateral low band width communication channel for transmitting said error signal from said transceiver to said mobile receiver, said means utilizing said error signal for improving said traveltime information.

Claim 20

A radio navigation system for determining the location of a mobile station, comprising a pair of transmitter stations at different fixed locations operating at respective carrier frequencies, a transceiver at a third fixed location, including a first precision frequency standard, and means for developing an error signal between said frequency standard and said received carrier frequency, and a mobile receiver including a second precision frequency standard synchronized with said first frequency standard, means for developing traveltime information from said received respective carrier frequencies and transmitting said traveltime information to said transmitter station controlled by said second precision frequency standard, a unilateral low band width communication channel for transmitting said error signal from said transceiver to said mobile receiver, said means utilizing said error signal for improving said traveltime information.

Claim 21

A radio navigation receiver for determining the location of a station from received first and second carrier waves transmitted from first and second fixedly located transmitters and a third fixedly located transmitter including an atomic clock synchronously operating with an atomic clock at the radio navigation receiver and developing error correction data of said atomic clock with respect to said first and second carrier waves, said receiver comprising derivative frequency and phase means for receiving the error correction data from said third transmitter and adjusting the frequency and phase of a signal related to the atomic clock frequency of said station receiver to equal nearly exactly the carrier waves from the first and second transmitters, and frequency and phase comparison means for developing the apparent difference in phase between the received carrier waves from said first and second transmitters and said corrected frequency signal related to the atomic clock frequency of said station receiver.

Claim 22

A radio navigation receiver for determining the location of a station from received first and second carrier waves transmitted from first and second fixedly located transmitters and a third fixedly located transmitter including an atomic clock synchronously operating with an atomic clock at the radio navigation receiver and developing error correction data of said atomic clock with respect to said first and second carrier waves, said receiver comprising derivative frequency and phase means for receiving the error correction data from said third transmitter and adjusting the frequency and phase of a signal related to the atomic clock frequency of said station receiver to equal nearly exactly the carrier waves from the first and second transmitters, and frequency and phase comparison means for developing the apparent difference in phase between the received carrier waves from said first and second transmitters and said corrected frequency signal related to the atomic clock frequency of said station receiver.

Claim 25

The method described in claim 16, wherein said error signals are converted to digital signals and broadcast to said station receiver via a low band broadcast channel.

Claim 26

The method described in claim 17, including the step of determining the traveltime of said detected frequencies between said station location and the respective ones of said first and second locations as a function of a preselected common frequency.

Claim 27

The method described in claim 18, including the steps of transmitting a first frequency related signal from said first location as a function of said first preselected frequency and said common preselected frequency, transmitting a second frequency related signal from said second location as a function of said second preselected frequency and said common preselected frequency, detecting said frequency related signals at said station location, and simultaneously selecting one of said detected frequency related signals and suppressing the other of said detected frequency related signals.