Method and system for synchronizing a time of day clock based on a satellite signal

• US 6,487,512 B1
• Filed: 10/16/2000
• Issued: 11/26/2002
• Est. Priority Date: 10/16/2000
• Status: Expired due to Term

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Tursich, Stephen B.
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US09/690,027
• Time in Patent Office: 771 Days
• Field of Search: 702/85, 702/89, 702/94-95, 702/149, 342/352, 342/356, 342/357.01, 342/357.06, 342/357.08, 342/357.12, 342/358, 342/357.17, 701/207, 701/213-214, 701/300
• US Class Current: 702/89
• CPC Class Codes: G04R 20/02 the radio signal being sent by a satellite, e.g. GPS

Abstract

A method and a system to synchronize a time of day clock of a clock system. The method and system include a portable satellite timing system at a first location receiving a satellite signal comprising a first time of day signal. An internal clock of the portable satellite timing system is calibrated based on the first time of day signal to generate a second time of day signal. The portable satellite timing system is transported to a second location and coupled to the clock system. The second time of day signal is transferred from the portable satellite timing system to the clock system and the time of day clock is synchronized based on the second time of day signal. After a time period, the portable satellite timing system is transported to the first location.

Claims

1. A method of synchronizing a time of day clock of a clock system, the method comprising:

receiving a satellite signal comprising a first time of day signal by a portable satellite timing system at a first location;

calibrating an internal clock of the portable satellite timing system based on the first time of day signal to generate a second time of day signal;

transporting the portable satellite timing system to a second location;

coupling the portable satellite timing system to the clock system;

transferring the second time of day signal from the portable satellite timing system to the clock system;

synchronizing the time of day clock based on the second time of day signal; and

transporting the portable satellite timing system to the first location after a time period.

2. The method as recited in claim 1, wherein the portable satellite timing system does not receive the satellite signal at the second location.

3. The method as recited in claim 1, further comprising:

maintaining the second time of day signal when portable satellite timing system is at the second location.

4. The method as recited in claim 1, further comprising:

receiving the satellite signal including a first clock signal with the portable satellite timing system at the first location and calibrating the portable satellite timing system based on the first clock signal to generate a second clock signal.

5. The method as recited in claim 4, further comprising:

transferring the second clock signal from the portable satellite timing system to the clock system and synchronizing the time of day clock based on the second clock signal.

6. The method as recited in claim 5, wherein the time period is based on an accuracy of an overtime of the second clock signal.

7. The method as recited in claim 5, wherein the second clock signal is about 10 MHz.

8. The method as recited in claim 1, further comprising:

receiving the satellite signal comprising a first pulse signal by a portable satellite timing system at the first location and calibrating an internal clock of the portable satellite timing system based on the first pulse signal to generate a second pulse signal.

9. The method as recited in claim 8, further comprising:

transferring the second pulse signal from the portable satellite timing system to the clock system and synchronizing the time of day clock based on the second pulse signal.

10. The method as recited in claim 9, wherein the second pulse signal is about 1 Hz.

11. The method as recited in claim 1, further comprising:

receiving the satellite signal comprising a first pulse signal and a first clock signal by the portable satellite timing system at the first location;

calibrating the internal clock of the portable satellite timing system based on the first pulse signal and the first clock signal to generate a second pulse signal and a second clock signal, respectively;

transferring the second pulse signal and the second clock signal from the portable satellite timing system to the clock system;

initializing the time of day clock based on the second time of day signal at an edge of the second pulse signal; and

incrementing the time of day clock based on the second clock signal.

12. The method as recited in claim 1, wherein the portable satellite timing system comprises a portable Global Positioning System.

13. The method as recited in claim 1, wherein the portable satellite timing system has battery power.

14. The method as recited in claim 1, wherein the portable satellite timing system has a satellite antenna.

15. The method as recited in claim 1, wherein the synchronizing of the time of day clock further comprises synchronizing the time of day clock to Universal Time Coordinated.