Method for determining drift with a digital compass

• US 6,446,003 B1
• Filed: 09/26/2000
• Issued: 09/03/2002
• Est. Priority Date: 07/12/2000
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Williams, Richard, Green, James C.
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US09/670,497
• Time in Patent Office: 707 Days
• Field of Search: 701/213, 701/214, 701/216, 701/224, 701/11, 342/357.08, 342/357.14, 244/175, 244/194, 244/195
• US Class Current: 701/213
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/53 Determining attitude
• CPC Class Codes: H04M 2250/10 including a GPS signal receiver

Abstract

An integrated position and direction system and method thereof for determining drift. The integrated position and direction system comprises a satellite positioning system and a digital compass. The satellite positioning system is used for determining position and heading, and the digital compass is used for determining direction. An amount of drift can be determined using the heading and the direction. Knowing the amount of drift, a course compensating for the drift can be determined. Thus, a craft that has drifted from its planned course can be directed to a course that will allow it to reach its intended destination.

Claims

1. An integrated position and direction system comprising:

a digital compass adapted to determine direction;

a satellite positioning system coupled to said digital compass, said satellite positioning system comprising;

a receiver adapted to receive satellite position determining signals; and

a controller coupled to said receiver, said controller for determining position and for determining heading;

wherein said satellite positioning system is adapted to determine an amount of drift using said heading and said direction and to determine a direction of drift using said heading and said direction; and

a display coupled to said satellite positioning system, said display for indicating said amount of drift and said direction of drift.

2. The integrated position and direction system of claim 1 wherein said display is also for indicating said heading and said direction.

3. The integrated position and direction system of claim 1 wherein said satellite positioning system is coupled to a navigation control system for a craft, wherein said navigation control system uses said amount of drift to determine a compensating course for said craft.

4. The integrated position and direction system of claim 1 further comprising:

a housing, wherein said satellite positioning system and said digital compass are disposed within said housing.

5. An integrated position and direction system comprising:

a satellite positioning system adapted to receive satellite position determining signals, said satellite positioning system also adapted to determine position and heading;

a digital compass coupled to said satellite position system, said digital compass adapted to determine direction; and

a controller coupled to said satellite positioning system and said digital compass, said controller for controlling the operations of said integrated position and direction system and said digital compass, wherein said controller is adapted to determine a direction of drift using said heading and said direction;

wherein said controller is also adapted to determine an amount of drift using said heading and said direction; and

a display coupled to said controller, said display for indicating said amount of drift and said direction of drift.

6. The integrated position and direction system of claim 5 wherein said display is also for indicating said direction and said heading.

7. The integrated position and direction system of claim 5 wherein said controller is coupled to a navigation control system for a craft, wherein said navigation control system uses said amount of drift to determine a compensating course for said craft.

8. The integrated position and direction system of claim 5 further comprising:

a housing, wherein said satellite positioning system, said controller and said digital compass are disposed within said housing.

9. A method of navigation using an integrated position and direction system, said method comprising:

a) determining heading using a satellite positioning system;

b) determining direction using a digital compass;

c) determining drift using said heading and said direction; and

d) displaying an amount of drift and a direction of drift on a display device.

10. The method as recited in claim 9 wherein said step d) further comprises the step of:

indicating said heading using said display device.

11. The method as recited in claim 9 wherein said step d) further comprises the step of:

indicating said direction using said display device.

12. The method as recited in claim 9 further comprising the step of:

determining a course compensating for said drift.

13. The method as recited in claim 9 further comprising the step of:

calibrating said digital compass using said heading.

14. A method of automatic navigation using an integrated position and direction system coupled to a navigation control system, said method comprising:

a) determining heading of a craft using a satellite positioning system of said integrated position and direction system;

b) determining direction of said craft using a digital compass of said integrated position and direction system;

c) determining drift of said craft using said heading and said direction;

d) determining a course compensating for said drift;

e) directing said craft to follow said course using said navigation control system; and

displaying an amount of drift and a direction of drift.

15. The method as recited in claim 14 further comprising the step of:

displaying said direction.

16. The method as recited in claim 14 further comprising the step of:

displaying said heading.