Automatic event recognition to trigger recording changes

• US 5,916,300 A
• Filed: 07/18/1997
• Issued: 06/29/1999
• Est. Priority Date: 07/18/1997
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Skoog, Paul, Allison, Michael Timo, Viney, Ian Timothy, Kirk, Geoffrey R.
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/896,929
• Time in Patent Office: 711 Days
• Field of Search: 701/213, 701/216, 701/35, 73/178 R, 342/357, 342/358, 342/457, 340/438, 340/439, 340/988, 360/48, 360/50, 360/51
• US Class Current: 701/213
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method

Abstract

A method and apparatus for automatic event detection and processing is provided. A positioning system receiver includes a position measurement device and a logging device. The position measurement device is configured to receive and process signals from a positioning system. The logging device is coupled to the position measurement device for recording data received from the position measurement device. The logging device records the data at a current logging rate. The positioning system receiver detects an event via an external sensor or with reference to satellite data, for example. In response to the event, the logging device automatically modifies data logging processing such as the current logging rate. Additionally, to allow a post processing system to go backwards in time relative to the event, the current logging rate may be increased for a predetermined amount of time preceding the occurrence of the event. According to another aspect of the invention, the data logging processing of a survey system, such as a real-time kinematic (RTK) system including a base reference station and a roving unit, may be altered based upon an event. Positioning system data is received. A first subset of the positioning system data is recorded prior to the event being detected. The first subset of positioning system data may include real-time roving unit position solutions. If the event has been detected, a second subset of the positioning system data is recorded. The second subset of the positioning system data may include data used for post processing.

Claims

1. A positioning system receiver for use in a post processed survey environment, comprising:

a position measurement device configured to receive and process signals from a positioning system; and

a logging device coupled to the position measurement device for recording position measurement data received from the position measurement device, the logging device recording position measurement data at a current logging rate, the logging device configured to automatically modify the current logging rate in response to an occurrence of a predetermined event.

2. The positioning system receiver of claim 1, wherein the current logging rate is temporarily increased for a predetermined amount of time after the occurrence of the predetermined event.

3. The positioning system receiver of claim 1, wherein the current logging rate is increased for a predetermined amount of time preceding the occurrence of the predetermined event.

4. The positioning system receiver of claim 1, wherein the current logging rate is increased for a predetermined amount of time preceding and subsequent to the occurrence of the predetermined event.

5. The positioning system receiver of claim 1, wherein the current logging rate switches from a first data logging rate to a second data logging rate in response to the occurrence of the predetermined event, the logging device further including:

a processor configured to record position measurement data;

a permanent storage coupled to the processor, the permanent storage having stored therein positioning system measurement data recorded by the processor at the first data logging rate; and

a temporary storage coupled to the processor, the temporary storage having stored therein positioning system measurement data recorded by the processor at the second data logging rate, wherein the processor is configured to selectively transfer a subset of the positioning system measurement data from the temporary storage to the permanent storage upon the occurrence of the predetermined event.

6. The positioning system receiver of claim 1, wherein the processor is further configured to selectively transfer a subset of the positioning system measurement data from the temporary storage to the permanent storage upon exhausting the temporary buffer.

7. A method of producing a data file containing positioning system data representing different data logging rates, the method comprising the steps of:

receiving positioning system data;

logging the positioning system data at a first data logging rate to a data file; and

automatically changing the first data logging rate to a second data logging rate for a predetermined amount of time preceding and subsequent to an occurrence of a predetermined event.

8. The method of claim 7, wherein the step of automatically changing the first data logging rate to a second data logging rate further includes the steps of:

storing the positioning system data to a temporary buffer at the second data logging rate; and

transferring a subset of the positioning system data from the temporary buffer to the data file upon detecting the predetermined event.

9. The method of claim 8, wherein the method further includes the steps of:

storing positioning system data to the data file at the second data logging rate for the predetermined amount of time following the predetermined event; and

storing positioning system data to the data file at the first data logging rate after the predetermined amount of time following the predetermined event.

10. The method of claim 7, wherein the positioning system data is received from a second data file.

11. The method of claim 7, wherein the positioning system data is received from a satellite positioning system.

12. A data logging device for use with a positioning system receiver, the data logging device comprising:

a processor;

a storage coupled to the processor for storing data received from a positioning system; and

a memory coupled to the processor, the memory having stored therein sequences of instructions which when executed by the processor, cause the processor to perform the steps of

receiving the data,

logging the data to a storage device at a first logging rate, and

automatically switching to a second logging rate upon detecting a predetermined event.

13. The data logging device of claim 12, further including a temporary buffer coupled to the processor, wherein sequences of instructions further cause the processor to perform the step of logging the data to the temporary buffer at the second logging rate.

14. The data logging device of claim 13, wherein the second data logging rate is X times N samples per second, the first data logging rate is N samples per second, the sequences of instructions further cause the processor to perform the step of upon determining that space in the temporary buffer has become exhausted, transferring a portion of data from the temporary buffer to the storage device, the portion of data representative of the first data logging rate.

15. The data logging device of claim 14, wherein the sequences of instructions further cause the processor to perform the steps of:

logging the data to the storage device at the second data logging rate for a predetermined amount of time; and

after logging for the predetermined amount of time, reverting back to logging to the storage device at the first data logging rate.

16. The data logging device of claim 13, wherein upon detecting the predetermined event the sequences of instructions further cause the processor to perform the step of transferring data from the temporary buffer to the storage device.

17. The data logging device of claim 12, wherein the step of logging the data to a storage device at a first logging rate further includes the steps of:

extracting a subset of data from the temporary buffer, the subset of data representative of data logged at a first logging rate; and

storing the subset of data to the storage device.

18. A recording apparatus for use with a positioning system receiver, the apparatus comprising:

a processor;

a storage coupled to the processor for storing data received from a positioning system; and

a memory coupled to the processor, the memory having stored therein sequences of instructions which when executed by the processor, cause the processor to perform the steps of

receiving the data,

logging a first subset of the data to a storage device if a predetermined event has not been detected; and

logging a second subset of the data to the storage device if the predetermined event has been detected.

19. The recording apparatus of claim 18, wherein the first subset corresponds to data representative of a first logging rate, wherein the second subset corresponds to data representative of a second logging rate, and wherein the sequences of instructions further cause the processor to perform the step of automatically switching to the second logging upon detecting a predetermined event.

20. In a surveying system, a method of data logging, the method comprising the steps of:

receiving positioning system data;

recording a first subset of the positioning system data prior to a predetermined event being detected; and

recording a second subset of the positioning system data if the predetermined event has been detected.

21. The method of claim 20, wherein the surveying system is a real-time kinematic (RTK) system including a base reference station and a roving unit, and the first subset of the positioning system data includes real-time roving unit position solutions, and the second subset of the positioning system data includes data used for post processing.

22. The method of claim 21, wherein the base reference station communicates information to the roving unit via a radio link, the radio link having a status, and the predetermined event is a change in the radio link status.

23. The method of claim 21, wherein the predetermined event is a loss of RTK initialization at the roving unit.

24. The method of claim 20, wherein the surveying system is a real-time kinematic (RTK) system including a base reference station and a roving unit, and the first subset of the positioning system data includes RTK initialization information, and the second subset of the positioning system data includes integer ambiguities.

25. The method of claim 20, wherein the surveying system is a real-time kinematic (RTK) system including a base reference station and a roving unit, and the first subset of the positioning system data includes RTK initialization information, and the second subset of the positioning system data includes raw measurement information.

26. The method of claim 20, wherein the survey system receives signals from a satellite positioning system, and the predetermined event is a change in visibility of one or more satellites.