User-controlled GPS receiver

• US 6,384,777 B1
• Filed: 12/13/1999
• Issued: 05/07/2002
• Est. Priority Date: 01/06/1998
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Woo, Arthur N., McBurney, Paul W.
• Primary Examiner(s): Phan, Dao
• Application Number:
  US09/458,837
• Time in Patent Office: 876 Days
• Field of Search: 342/357.01, 342/357.12, 342/357.13
• US Class Current: 342/357.31
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver

Abstract

A system and method which enables a user platform to perform low level control of a channel unit which performs acquisition and tracking of Global Positioning System (GPS) signals processing the measurement platform which includes the channel and that performs all satellite tracking functions which are driven by interrupts. Intermediate measurements data generated therefrom, for example code phase, carrier phase and Doppler, are communicated to a user platform which computes receiver position and time. As a result, the user platform can easily be configured to perform user-specific processes without incurring conflicts with the interrupt driven processes occurring on the measurement platform. Furthermore, the user platform is configured to issue commands to the channel unit to control the operation of the measurement platform. Thus, the performance of the measurement platform can be tailored specifically to the end user application.

Claims

1. A Global Positioning System (GPS) method comprising:

receiving a command with one or more parameters from a user platform by a measurement platform that is processing real time GPS signals, wherein the receiving of the command includes receiving a preposition command for controlling prepositioning by the measurement platform during tracking and acquisition of GPS signals; and

adjusting a low level operation of the measurement platform in accordance with the received command and one or more parameters from the user platform.

2. The method of claim 1, wherein the receiving of the command includes receiving of a power control command for controlling power use in the measurement platform.

3. The method of claim 1, wherein the adjusting of the low level operation includes adjusting the measurement platform to switch between a power up state to a power down state reducing for power consumption in response to the power control command.

4. The method of claim 2, wherein the adjusting of the low level operation includes tracking of GPS signals by the measurement platform without outputting data to the user platform in response to the power control command.

5. The method of claim 1, wherein the adjusting of the low level operation includes setting a size of a search window by the measurement platform in response to the preposition command.

6. The method of claim 5, wherein the adjusting of the low level operation includes automatically adjusting the search window size according to an acceleration as applied to a dynamic model.

7. The method of claim 1, wherein the adjusting of the low level operation includes performing prepositioning immediately after receiving the preposition command or performing prepositioning after a current dwell.

8. The method of claim, 1, wherein the receiving of the command includes receiving of an output data command for controlling data output to the user platform.

9. The method of claim 8, wherein the adjusting of the low level operation includes separately controlling the data output to be observable data and carrier phase data.

10. The method of claim 8, wherein the adjusting of the low level operation includes controlling the output data rate using output data command.

11. The method of claim 1, wherein the receiving of the command includes receiving a signal filtering command for filtering out signals that do not exceed a specified threshold.

12. A machine-readable medium providing instructions, which if executed by a processor, causes the processor to perform an operation comprising:

receiving a command with one or more parameters from a user platform by a measurement platform that is processing real time GPS signals, wherein the receiving of the command includes receiving a preposition command for controlling prepositioning during tracking and acquisition of GPS signals; and

adjusting a low level operation of the measurement platform in accordance with the received command and one or more parameters from the user platform.

13. The machine-readable medium of claim 12, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

receiving a power control command for controlling power use in the measurement platform.

14. The machine-readable medium of claim 13, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

adjusting the measurement platform to switch between a power up state to a power down state for reducing power consumption in response to the power control command.

15. The machine-readable medium of claim 13, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

tracking of GPS signals by the measurement platform without outputting data to the user platform in response the power control command.

16. The machine-readable medium of claim 12, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

setting a size of a search window by the measurement platform in response to the preposition command.

17. The machine-readable medium of claim 16, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

automatically adjusting the search window size according to an acceleration as applied to a dynamic model.

18. The machine-readable medium of claim 12, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

performing prepositioning immediately after receiving the preposition command or before performing prepositioning after a current dwell.

19. The machine-readable medium of claim 12, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

receiving an output data command for controlling data output to the user platform.

20. The machine-readable medium of claim 19, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

separately controlling the data output to be observable data and carrier phase data.

21. The machine-readable medium of claim 20, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

controlling the output data rate using the output data command.

22. The machine-readable medium of claim 12, further providing instructions, which if executed by the processor, causes the processor to perform an operation comprising:

receiving a signal filtering command for filtering out signals that do not exceed a specified threshold.