Apparatus and method for determination of a receiver position
First Claim
1. A method of determination of a receiver fixed position using global positioning system (GPS), comprising:
- obtaining pseudo-range output over a predetermined measurement period from a GPS receiver, the pseudo-range output measured from an ensemble of space vehicles at each of a plurality of times t over the measurement period;
determining the historical ephemerides of the ensemble of space vehicles corresponding to each of the plurality of times t;
determining a position solution for each of the plurality of times t utilizing the pseudo-range output and the ephemerides; and
averaging the position solution for each of the times t over the measurement period.
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Abstract
A method of accurate determination of a fixed position using global positioning system uses pseudo-range output over a predetermined measurement period from a stand-alone GPS receiver located at the fixed position, the pseudo-range output being measured from an ensemble of space vehicles at each time t over the measurement period, and historical ephemerides of the ensemble of space vehicles over the same measurement period to eliminate errors caused by selective availability. The historical ephemerides of the ensemble of space vehicles corresponding to each measurement time t are determined, and using the pseudo-range output and the historical ephemerides, a position solution at each time t is computed. The accurate position in earth-centered earth-fixed coordinates is then the average of all the position solutions at each time t over the measurement period.
23 Citations
13 Claims
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1. A method of determination of a receiver fixed position using global positioning system (GPS), comprising:
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obtaining pseudo-range output over a predetermined measurement period from a GPS receiver, the pseudo-range output measured from an ensemble of space vehicles at each of a plurality of times t over the measurement period; determining the historical ephemerides of the ensemble of space vehicles corresponding to each of the plurality of times t; determining a position solution for each of the plurality of times t utilizing the pseudo-range output and the ephemerides; and averaging the position solution for each of the times t over the measurement period. - View Dependent Claims (2, 3, 4, 5)
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6. A method of determination of a receiver position using a stand-alone global positioning system (GPS) receiver, the receiver generating a plurality of pseudo-range data over a measurement period, comprising:
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receiving the plurality of pseudo-range data over the measurement period, the pseudo-range data measured for an ensemble of at least four space vehicles at each of a plurality of times t over the measurement period; receiving historical ephemerides of the same ensemble of space vehicles over the measurement period; determining from the received ephemerides an orbit for each space vehicle; determining intermediate historical ephemerides between the historical ephemerides in each orbit for each of the plurality of times t during the measurement period; determining a position solution for each of the plurality of times t utilizing the plurality of pseudo-range data and the ephemerides; and averaging the position solution for each of the times t over the measurement period. - View Dependent Claims (7, 8, 9)
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10. A stand-alone global positioning system (GPS) receiver having a post-processor for accurate determination of a fixed position, the post-processor programmed to:
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receive a plurality of pseudo-range measurements over a predetermined measurement period, the pseudo-range measurements determined from an ensemble of space vehicles at each of a plurality of times t over the measurement period; obtain historical ephemerides of the ensemble of space vehicles over the measurement period, the historical ephemerides being free of the selective availability broadcast ephemeris error; determine the historical ephemerides of the ensemble of space vehicles corresponding to each time t in response to the obtained historical ephemerides; use the plurality of pseudo-range measurements and the historical ephemerides to determine a position solution at each time t; and average the position solutions over the measurement period. - View Dependent Claims (11, 12, 13)
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Specification