Mobile unit positioning device
First Claim
1. A mobile-unit positioning device in which phases of pseudo noise codes carried on satellite signals from a plurality of satellites are observed at a mobile unit to measure a position of the mobile unit, comprising:
- a pseudo-distance measuring part measuring a pseudo distance for every satellite between one of the plurality of satellites and the mobile unit during a stop of the mobile unit using an observed value of the pseudo noise code phase acquired during a stop of the mobile unit;
an error-index-value computing part computing an error index value for every satellite indicating an error of the measured pseudo distance, based on the pseudo distances measured by the pseudo-distance measuring part at a plurality of points in time during a stop of the mobile unit;
a weighting-factor determining part determining a weighting factor for every satellite based on the error index value for every satellite computed by the error-index-value computing part; and
a positioning computation part performing a weighted positioning computation using the weighting factor for every satellite determined by the weighting-factor determining part, to determine a position of the mobile unit during movement using an observed value of the pseudo noise code phase acquired during movement of the mobile unit.
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Accused Products
Abstract
In a mobile-unit positioning device, phases of pseudo noise codes carried on satellite signals from satellites are observed at a mobile unit to measure a position of the mobile unit. A pseudo distance between one of the satellites and the mobile unit is measured for every satellite during a stop of the mobile unit using an observed value of the phase acquired during a stop of the mobile unit. An error index value indicating an error of the measured distance is computed based on the distances measured at points in time during a stop of the mobile unit. A weighting factor is determined based on the index value computed for every satellite. A weighted positioning computation using the determined weighting factor is performed to determine a position of the mobile unit during movement using an observed value of the phase acquired during movement.
11 Citations
10 Claims
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1. A mobile-unit positioning device in which phases of pseudo noise codes carried on satellite signals from a plurality of satellites are observed at a mobile unit to measure a position of the mobile unit, comprising:
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a pseudo-distance measuring part measuring a pseudo distance for every satellite between one of the plurality of satellites and the mobile unit during a stop of the mobile unit using an observed value of the pseudo noise code phase acquired during a stop of the mobile unit; an error-index-value computing part computing an error index value for every satellite indicating an error of the measured pseudo distance, based on the pseudo distances measured by the pseudo-distance measuring part at a plurality of points in time during a stop of the mobile unit; a weighting-factor determining part determining a weighting factor for every satellite based on the error index value for every satellite computed by the error-index-value computing part; and a positioning computation part performing a weighted positioning computation using the weighting factor for every satellite determined by the weighting-factor determining part, to determine a position of the mobile unit during movement using an observed value of the pseudo noise code phase acquired during movement of the mobile unit. - View Dependent Claims (2, 3)
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4. A mobile-unit positioning device in which Doppler frequencies of carriers of satellite signals from a plurality of satellites are observed at a mobile unit to measure a speed of the mobile unit, comprising:
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a mobile-unit-speed computing part computing a speed of the mobile unit for every satellite during a stop of the mobile unit using an observed value of a Doppler frequency acquired during a stop of the mobile unit; an error-index-value computing part computing an error index value for every satellite indicating an error of the computed mobile unit speed, based on the mobile unit speeds computed by the mobile-unit-speed computing part at a plurality of points in time during a stop of the mobile unit; a weighting-factor determining part determining a weighting factor for every satellite based on the error index value for every satellite computed by the error-index-value computing part; and a positioning computation part performing a weighted positioning computation using the weighting factor for every satellite determined by the weighting-factor determining part, to determine a speed of the mobile unit during movement using an observed value of the Doppler frequency acquired during movement of the mobile unit. - View Dependent Claims (5, 6, 7, 8, 9)
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10. A mobile-unit positioning method in which phases of pseudo noise codes carried on satellite signals from a plurality of satellites are observed at a mobile unit to measure a position of the mobile unit, comprising the steps of:
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measuring a pseudo distance for every satellite between one of the plurality of satellites and the mobile unit during a stop of the mobile unit using an observed value of the pseudo noise code phase acquired during a stop of the mobile unit; computing an error index value for every satellite indicating an error of the measured pseudo distance, based on the pseudo distances measured in the measuring step at a plurality of points in time during a stop of the mobile unit; determining a weighting factor for every satellite based on the error index value for every satellite computed in the computing step; and performing a weighted positioning computation using the weighting factor for every satellite determined in the determining step, to determine a position of the mobile unit during movement using an observed value of the pseudo noise code phase acquired during movement of the mobile unit.
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Specification