Time determination in satellite positioning system receivers and methods therefor
First Claim
1. A method in a Global Positioning System (GPS) receiver, comprising:
- determining pseudorange measurements for at least four satellites at a coarse time corresponding to the pseudorange measurement;
determining an offset time between a periodic GPS event of one of the four satellites and the coarse time;
determining a time correction delta based upon the period of the Periodic GPS event, the offset time and the coarse time if an error of the coarse time is less than ½
the period of the periodic GPS event;
determining corrected time based upon the coarse time and the time correction delta if the error of the coarse time is less than ½
the period of the Periodic GPS event.
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Accused Products
Abstract
Method in a Global Positioning System (GPS) receivers, including determining pseudorange (PNR) measurements for at least four satellites (210), determining a coarse time (220) corresponding to the pseudorange measurement, determining an offset time (240) between a periodic GPS event of one of the four satellites and the coarse time, determining a time correction delta (250) based upon the period of the Periodic GPS event, the offset time and the coarse time if an error of the coarse time is less than ½ the period of the periodic GPS event, and determining corrected time (260) based upon the coarse time and the time correction delta if the error of the coarse time is less than ½ the period of the periodic GPS event.
214 Citations
54 Claims
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1. A method in a Global Positioning System (GPS) receiver, comprising:
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determining pseudorange measurements for at least four satellites at a coarse time corresponding to the pseudorange measurement;
determining an offset time between a periodic GPS event of one of the four satellites and the coarse time;
determining a time correction delta based upon the period of the Periodic GPS event, the offset time and the coarse time if an error of the coarse time is less than ½
the period of the periodic GPS event;
determining corrected time based upon the coarse time and the time correction delta if the error of the coarse time is less than ½
the period of the Periodic GPS event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method in a Global Positioning System (GPS) receiver, comprising:
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determining pseudorange measurements for at least four satellites;
determining a minimum navigation solution residual magnitude time;
determining an offset time between a periodic GPS event of one of the four satellites and the minimum navigation solution residual magnitude time;
determining a time correction delta based upon the period of the Periodic GPS event, the offset time, and the minimum navigation solution residual magnitude time;
determining corrected time based upon the time correction delta and the minimum navigation solution residual magnitude time. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A method in a Global Positioning System (GPS) receiver, comprising:
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determining pseudorange measurements for at least four satellites;
determining an offset time between a periodic OPS event of one of the four satellites and a time of the pseudorange measurements;
sending an over-the-air message comprising the pseudorange measurements, the offset time determined, a satellite ID for the satellite of the periodic GPS event, the over-the-air message for position computation of the GPS receiver at a remote location. - View Dependent Claims (40)
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41. A method of computing location of a GPS receiver at remote position computation equipment, comprising:
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at the remote position computation equipment, receiving an over-the-air message comprising pseudorange measurements for at least four satellites, an offset time, and a satellite ID for one of the four satellites, the offset time is a time between a periodic GPS event of the satellite corresponding to the satellite ID and a time of the pseudorange measurements;
at the remote position computation equipment, determining a minimum navigation solution residual magnitude time;
at the remote position computation equipment, determining a time correction delta based upon the period of the Periodic GPS event, the offset time, and the minimum navigation solution residual magnitude time;
at the remote position computation equipment, determining corrected time based upon the time correction delta and the minimum navigation solution residual magnitude time.
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42. A method of computing location of a GPS receiver at remote position computation equipment, comprising:
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at the remote position computation equipment, receiving an over-the-air message comprising pseudorange measurements for at least four satellites, a pseudorange measurement time, an offset time, and a satellite ID for one of the four satellites, the offset time is a time between a periodic GPS event of the satellite corresponding to the satellite ID and the pseudorange measurement time;
at the remote position computation equipment, determining a time correction delta based upon the period of the Periodic GPS event, the offset time, and the pseudorange measurement time;
at the remote position computation equipment, determining corrected time based upon the time correction delta and the pseudorange measurement time.
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43. A method in a Global Positioning System (GPS) receiver, comprising:
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determining pseudorange measurements for at least four satellites;
determining an offset time between a periodic GPS event of one of the four satellites and the pseudorange measurement time;
determining a pseudorange measurement local time tag corresponding to a time of the pseudorange measurements;
sending an over-the-air message comprising the pseudorange measurements, and the local time tag;
the over-the-air mess age for position computation of the GPS receiver at a remote location. - View Dependent Claims (44, 45)
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46. A method of computing time in a remote position computation equipment, comprising:
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receiving an over-the-air message from a remote GPS receiver;
said over-the-air message containing pseudorange measurements for at least four satellites, a pseudorange measurement local time tag, determining a minimum navigation solution residual magnitude time;
determining a time difference between the pseudorange measurement local time tag and the minimum navigation solution residual magnitude time;
determining a time correction delta based upon a modulus of the time difference and a repeat time of a periodic GPS event;
determining corrected time based upon the time correction delta and the minimum navigation solution residual magnitude time. - View Dependent Claims (47)
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48. A method in a Global Positioning System (GPS) receiver, comprising:
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determining pseudorange measurements for at least four satellites;
determining an offset time between a periodic GPS event of one of the four satellites and a time of the pseudorange measurements;
obtaining a time correction delta based upon the offset time and the time of the pseudorange measurements;
obtaining a corrected time based upon the time correction delta and the time of the pseudorange measurements;
improving accuracy of a local real time clock based upon the corrected time. - View Dependent Claims (49, 50, 51, 52, 53, 54)
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Specification