Apparatus and methods to share time and frequency data between a host processor and a satellite positioning system receiver
First Claim
1. A host processor in communication with a SPS receiver comprising:
- a real-time clock;
a time computing device to estimate a SPS time based on the real-time clock;
a conversion factor adjuster to adjust the time computing device to synchronize a time developed from the real-time clock with a SPS time received from the SPS receiver and to correct a local frequency error of the real-time clock; and
a transmitter to transmit an electronic pulse at substantially the estimated SPS time followed by a message containing a first value representative of the estimated SPS time.
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Accused Products
Abstract
Methods and apparatus to share time and frequency data between a host processor and a satellite position system (SPS) receiver in a satellite positioning system are disclosed. An example method disclosed herein generates a host processor local time based on a real-time clock associated with the host processor; adjusts the host processor local time to synchronize with a SPS time received from the SPS receiver and to correct a local frequency error of the real-time clock of the host processor; calculates an estimated SPS time based on the adjusted real-time clock signal of the host processor; and attempts to fix a SPS time and a position of the SPS receiver from SPS signals received from a plurality of SPS satellites based on the estimated SPS time.
21 Citations
26 Claims
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1. A host processor in communication with a SPS receiver comprising:
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a real-time clock; a time computing device to estimate a SPS time based on the real-time clock; a conversion factor adjuster to adjust the time computing device to synchronize a time developed from the real-time clock with a SPS time received from the SPS receiver and to correct a local frequency error of the real-time clock; and a transmitter to transmit an electronic pulse at substantially the estimated SPS time followed by a message containing a first value representative of the estimated SPS time. - View Dependent Claims (2)
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3. A SPS receiver in communication with a host processor comprising:
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a receiver to receive an estimated SPS time based on a real-time clock signal of the host processor; and a radio processor to receive SPS signals from a plurality of satellites, wherein the radio processor attempts to derive a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites and the estimated SPS time; a time recorder to record;
(a) a first value representative of a local time of the SPS receiver substantially simultaneous to the estimated SPS time;
(b) a second value representative of a SPS time value derived from the received SPS time signals; and
(c) a third value representative of a second local time of the SPS receiver substantially simultaneous to the derived SPS time. - View Dependent Claims (4, 5, 6)
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7. A SPS receiver in communication with a host processor comprising:
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a radio processor to receive SPS signals from a plurality of satellites, wherein the radio processor attempts to derive a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites; wherein the SPS receiver outputs the derived SPS time to facilitate estimation of SPS times by the host processor; and a time recorder to record;
(a) a first value representative of a first local time of the SPS receiver;
(b) a second value representative of a SPS time value derived from the received SPS time signals; and
(c) a third value representative of a second local time of the SPS receiver substantially simultaneous to the derived SPS time. - View Dependent Claims (8, 9, 10)
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11. A method of sharing time and frequency data between a host processor and a SPS receiver comprising:
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developing a local time of the host processor based on a real-time clock associated with the host processor; deriving a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites and the local time of the host processor; and using the derived SPS time to adjust a parameter associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A method of sharing time and frequency data between a host processor and a SPS receiver comprising:
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developing a local time of the host processor based on a real-time clock associated with the host processor; deriving a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites; using the derived SPS time to adjust parameters associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock; and calculating an estimate of SPS time based on the local time of the host processor developed from the real-time clock associated with the host processor; wherein deriving the SPS time and the SPS receiver location from the SPS signals received from the plurality of SPS satellites uses the estimated SPS time; wherein calculating the estimate of SPS time based on the local time of the host processor developed from the real-time clock associated with the host processor comprises using a programmable scale factor; and wherein using the derived SPS time to adjust the parameters associated with developing the local time of the host processor based on the real-time clock to correct the local frequency error of the real-time clock comprises updating the programmable scale factor based upon a first difference between the estimated SPS time and a first local time of the SPS receiver and a second difference between a second local time of the SPS receiver and the derived SPS time.
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19. A method of sharing time and frequency data between a host processor and a SPS receiver comprising:
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developing a local time of the host processor based on a real-time clock associated with the host processor; deriving a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites; using the derived SPS time to adjust parameters associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock; calculating an estimate of SPS time based on the local time of the host processor developed from the real-time clock associated with the host processor; wherein deriving the SPS time and the SPS receiver location from the SPS signals received from the plurality of SPS satellites uses the estimated SPS time; developing a second local time from a second real-time clock; computing a first difference between the estimate of SPS time and the second local time; and computing a second difference between the derived SPS time and a third local time developed from the second local clock; wherein adjusting parameters associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock uses the first and second differences. - View Dependent Claims (20, 21)
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22. A method of sharing time and frequency data between a host processor and a SPS receiver comprising:
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developing a local time of the host processor based on a real-time clock associated with the host processor; deriving a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites; using the derived SPS time to adjust parameters associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock; calculating an estimate of SPS time based on the local time of the host processor developed from the real-time clock associated with the host processor; wherein deriving the SPS time and the SPS receiver location from the SPS signals received from the plurality of SPS satellites uses the estimated SPS time; and
wherein the host processor and the SPS receiver are located in a single housing.
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23. A method of sharing time and frequency data between a host processor and a SPS receiver comprising:
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developing a local time of the host processor based on a real-time clock associated with the host processor; deriving a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites; and using the derived SPS time to adjust parameters associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock; wherein developing the local time based on the real-time clock associated with the host processor comprises using a programmable scale factor; and wherein using the derived SPS time to adjust the parameters associated with developing the first local time of the host processor based on the real-time clock to correct the local frequency error of the real-time clock comprises updating the programmable scale factor based upon a first difference between a local time of the host processor and a first local time of the SPS receiver and a second difference between a second local time of the SPS receiver and the derived SPS time.
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24. A method of sharing time and frequency data between a host processor and a SPS receiver comprising:
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developing a local time of the host processor based on a real-time clock associated with the host processor; deriving a SPS time and SPS receiver location from SPS signals received from a plurality of SPS satellites; using the derived SPS time to adjust parameters associated with developing the local time of the host processor based on the real-time clock to correct a local frequency error of the real-time clock; developing a second local time from a second real-time clock; computing a first difference between a local time of the host processor and the second local time; and computing a second difference between the derived SPS time and a third local time developed from the second local clock; wherein adjusting parameters associated with developing the local time of the host processor based on the real-time clock to correct the local frequency error of the real-time clock uses the first and second differences. - View Dependent Claims (25, 26)
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Specification