Position estimation using a network of a global-positioning receivers
First Claim
1. A method of estimating the location of a rover station (R) with the use of a first base station (B1) and a second base station (B2), the method comprising:
- (a) receiving the known locations of the first base station and the second base station;
(b) obtaining a first time offset representative of the time difference between the clocks of the first and second base stations;
(c) receiving measured satellite navigation data as received by the rover, the first base station, and the second base station;
(d) generating a first set of residuals of differential navigation equations associated with a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured satellite navigation data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
(e) generating a second set of residuals of differential navigation equations associated with a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured satellite navigation data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station; and
(f) generating an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, and the time offset between the clocks of the first and second base stations.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed are methods and apparatuses for determining the position of a roving receiver in a coordinate system using at least two base-station receivers, which are located at fixed and known positions within the coordinate system. The knowledge of the precise locations of the base-station receivers makes it possible to better account for one or all of carrier ambiguities, receiver time offsets, and atmospheric effects encountered by the rover receiver, and to thereby increase the accuracy of the estimated receiver position of the rover. Baselines are established between the rover and each base-station, and baselines are established between the base stations. Navigation equations, which have known quantities and unknown quantities, are established for each baseline. Unknowns for the baseline between base stations are estimated, and then used to correlate and reduce the number of unknowns associated with rover baselines, thereby improving accuracy of the rover'"'"'s estimated position.
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Citations
78 Claims
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1. A method of estimating the location of a rover station (R) with the use of a first base station (B1) and a second base station (B2), the method comprising:
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(a) receiving the known locations of the first base station and the second base station;
(b) obtaining a first time offset representative of the time difference between the clocks of the first and second base stations;
(c) receiving measured satellite navigation data as received by the rover, the first base station, and the second base station;
(d) generating a first set of residuals of differential navigation equations associated with a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured satellite navigation data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
(e) generating a second set of residuals of differential navigation equations associated with a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured satellite navigation data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station; and
(f) generating an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, and the time offset between the clocks of the first and second base stations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of estimating the location of a rover station (R) with the use of a first base station (B1), a second base station (B2), and a third base station (B3), the method comprising:
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(a) receiving the known locations of the first base station, the second base station, and the third base station;
(b) obtaining a first set of satellite-phase cycle ambiguities related to the baseline between the first and second base stations, and a second set of satellite-phase cycle ambiguities related to the baseline between the first and third base stations;
(c) obtaining a first time offset representative of the time difference between the clocks of the first and second base stations, and a second time offset representative of the time difference between the clocks of the first and third base stations;
(d) obtaining measured satellite data as received by the rover, the first base station, the second base station, and the third base station;
(e) generating a first set of residuals of differential navigation equations for a first baseline (R-B1) between the rover and the first base station, the residuals being related to at least the measured satellite data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
(f) generating a second set of residuals of differential navigation equations for a second baseline (R-B2) between the rover and the second base station, the residuals being related to at least the measured satellite data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station;
(g) generating a third set of residuals of differential navigation equations for a third baseline (R-B3) between the rover and the third base station, the residuals being related to at least the measured satellite data received by the rover station and the third base station, the locations of the satellites, and the locations of the rover station and the third base station;
(h) generating an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, the third set of residuals, the first time offset, the first set of satellite-phase cycle ambiguities, the second time offset, and the second set of satellite-phase cycle ambiguities. - View Dependent Claims (29, 30, 31, 32, 33)
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34. A method of estimating the location of a rover station (R) with the use of a first base station (B1) and a second base station (B2), the method comprising:
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(a) receiving the known locations of the first base station and the second base station;
(b) obtaining the time offset representative of the time difference between the clocks of the first and second base stations, and a set of satellite-phase cycle ambiguities related to the baseline between the first and second base stations;
(c) obtaining measured satellite data as received by the rover, the first base station, and the second base station;
(d) generating a first set of residuals of differential navigation equations for a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured satellite data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
(e) generating a second set of residuals of differential navigation equations for a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured satellite data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station; and
(f) estimating the rover'"'"'s location from the first set of residuals, the second set of residuals, the time offset between the clocks of the first and second base stations, and the set of satellite-phase cycle ambiguities related to the baseline between the first and second base stations.
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35. A computer program product for directing a computer processor to estimate the location of a rover station (R) with the use of a first base station (B1) and a second base station (B2), the locations of the first base station and the second base station, and measured satellite data as received by the rover, the first base station, and the second base station, the computer program product comprising:
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a computer-readable medium;
an initial set of instructions embodied on the computer-readable medium which directs the data processor to receive the known positions of the base stations;
a first set of instructions embodied on the computer-readable medium which directs the data processor to obtain a first time offset representative of the time difference between the clocks of the first and second base stations;
a second set of instructions embodied on the computer-readable medium which directs the data processor to generate a first set of residuals of differential navigation equations associated with a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
a third set of instructions embodied on the computer-readable medium which directs the data processor to generate a second set of residuals of differential navigation equations associated with a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station; and
a fourth set of instructions embodied on the computer-readable medium which directs the data processing system to generate an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, and the time offset between the clocks of the first and second base stations. - View Dependent Claims (36, 37, 38, 39)
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40. A computer program product for directing a data processor to estimate the location of a rover station (R) with the use of a first base station (B1), a second base station (B2), a third base station (B3), the locations of the base stations, and measured satellite data as received by the rover and the base stations, the computer program product comprising:
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a computer-readable medium;
an initial set of instructions embodied on the computer-readable medium which directs the data processor to receive the known positions of the base stations;
a first set of instructions embodied on the computer-readable medium which directs the data processor to obtain a first time offset representative of the time difference between the clocks of the first and second base stations;
a second set of instructions embodied on the computer-readable medium which directs the data processor to obtain a second time offset representative of the time difference between the clocks of the first and third base stations;
a third set of instructions embodied on the computer-readable medium which directs the data processor to obtain a third time offset representative of the time difference between the clocks of the second and third base stations;
a fourth set of instructions embodied on the computer-readable medium which directs the data processor to generate a first set of residuals of differential navigation equations associated with a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
a fifth set of instructions embodied on the computer-readable medium which directs the data processor to generate a second set of residuals of differential navigation equations associated with a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station;
a sixth set of instructions embodied on the computer-readable medium which directs the data processor to generate a third set of residuals of differential navigation equations associated with a third baseline (R-B3) between the rover and the third base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the third base station, the locations of the satellites, and the locations of the rover station and the third base station; and
a seventh set of instructions embodied on the computer-readable medium which directs the data processor to generate an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, the third set of residuals, the time offset between the clocks of the first and second base stations, and the time offset between the clocks of the second and third base stations. - View Dependent Claims (41, 42, 43, 44, 45)
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46. An apparatus for estimating the location of a rover station (R) with the use of a first base station (B1) and a second base station (B2), the apparatus comprising:
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(a) means for receiving the locations of the first base station and the second base station;
(b) means for obtaining a first time offset representative of the time difference between the clocks of the first and second base stations;
(c) means for receiving measured satellite navigation data as received by the rover, the first base station, and the second base station;
(d) means for generating a first set of residuals of differential navigation equations associated with a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured satellite navigation data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
(e) means for generating a second set of residuals of differential navigation equations associated with a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured satellite navigation data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station; and
(f) means for generating an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, and the time offset between the clocks of the first and second base stations. - View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71)
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72. An apparatus for estimating the location of a rover station (R) with the use of a first base station (B1) and a second base station (B2), the apparatus comprising:
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a first antenna which receives navigation satellite signals, a second antenna which receives data signals from the base stations;
a main processor coupled to an instruction memory and a data memory, a satellite-signal demodulator coupled to the first antenna and the main processor, the satellite-signal demodulator demodulating the satellite signals and providing measured satellite data related to the rover'"'"'s location to the main processor;
a base-station information demodulator coupled to the second antenna and the main processor, the base-station information demodulator demodulating the data signals transmitted by the base stations and providing data demodulated therefrom to the main processor, the data including at least the locations of the base stations and the measured satellite data as received by the base stations;
an initial set of instructions embodied in the instruction memory which directs the main processor to receive the known positions of the base stations;
a first set of instructions embodied in the instruction memory which directs the main processor to obtain a first time offset representative of the time difference between the clocks of the first and second base stations;
a second set of instructions embodied in the instruction memory which directs the main processor to generate a first set of residuals of differential navigation equations associated with a first baseline (R-B1) between the rover and the first base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the first base station, the locations of the satellites, and the locations of the rover station and the first base station;
a third set of instructions embodied in the instruction memory which directs the main processor to generate a second set of residuals of differential navigation equations associated with a second baseline (R-B2) between the rover and the second base station, the residuals being related to the measured pseudo-range satellite data received by the rover station and the second base station, the locations of the satellites, and the locations of the rover station and the second base station; and
a fourth set of instructions embodied in the instruction memory which directs the main processor to generate an estimate of the rover'"'"'s location from the first set of residuals, the second set of residuals, and the time offset between the clocks of the first and second base stations. - View Dependent Claims (73, 74, 75, 76, 77, 78)
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Specification