Managed traverse system and method to acquire accurate survey data in absence of precise GPS data

• US 7,619,561 B2
• Filed: 11/20/2008
• Issued: 11/17/2009
• Est. Priority Date: 05/10/2005
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Scherzinger, Bruno
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): LIU, HARRY K
• Application Number:
  US12/313,560
• Publication Number:
  US 20090115655A1
• Time in Patent Office: 362 Days
• Field of Search: 342/357.17, 701/217
• US Class Current: 342/357.31
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G01C 15/06 Surveyors' staffs; Movable markers
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01S 19/485 whereby the further system is an optical system or imaging system
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/51 Relative positioning

Abstract

A method and system obtains precise survey-grade position data of target points in zones where precise GPS data cannot be obtained, due to natural or man-made objects such as foliage and buildings. The system comprises a GPS receiver mounted on a survey pole, with an inertial measurement unit (IMU) and an electronic distance meter (EDM) also mounted on the pole. The system and method obtains GPS data when outside the zone and uses the IMU inside the zone to traverse to a target point, using the EDM to obtain data reduce accumulated errors which occur with the IMU.

Claims

1. A surveying system for determining the position of a target in a zone in which precise survey grade location data cannot be obtained using satellite position receivers, comprising:

a satellite position receiver for determining the position of a starting point outside the perimeter of the zone;

a measurement system configured to obtain relative position information as one traverses from the starting point to the target, said measurement system subject to the accumulation of tracking errors during said traversal and configured to obtain aiding position information to reduce the accumulation of errors during said traversal; and

a processing system configured to compute the position of the target using the starting point position, the relative position information, and the aiding position information, whereby the position of the target so computed has greater precision than that computed using only relative position information.

2. The system according to claim 1, further comprising a survey pole onto which the satellite position receiver is mounted, and wherein the measurement system comprises an EDM with a laser mounted on the pole.

3. The system according to claim 1, further comprising a survey pole onto which the satellite position receiver is mounted, and wherein the measurement system comprises an IMU mounted on the pole.

4. The system according to claim 1, further comprising a survey pole onto which the satellite position receiver is mounted, and wherein the measurement system comprises an EDM with a laser, and an IMU mounted on the pole.

5. The system according to claim 3, wherein the measurement system obtains relative position information of a plurality of intermediate reference points within the zone as one traverses from the starting point to the target said relative position information at each point being relative to the previous point, and wherein the measurement system obtains aiding information for at least one of the intermediate reference points by obtaining relative position data from the intermediate reference point to the starting point.

6. The system according to claim 5, wherein the measurement system comprises an IMU to obtain relative position information, and wherein the measurement system comprises an EDM to obtain the aiding information.

7. A surveying system for determining the position of an object in a zone where a satellite position receiver cannot locate the object with sufficient precision for a survey grade application, comprising:

a position locator configured to determine the position of a first reference point outside a perimeter of the zone using a satellite position receiver and satellite position signals, said position locator obtaining relative position information of the object location relative to the first reference point during a traversal inside the zone from the first reference point toward the object, accumulating tracking errors during said traversal; and

an aiding device configured to reduce the accumulated tracking errors during traversal to the target inside the zone, by determining position relative to at least one reference location whose position is known.

8. A system for determining the location of a target within a zone in which satellite signals are ineffective for obtaining error-free location, the system comprising:

At least one known location outside the zone;

At least one known reference point location, the location of said one known reference point being based upon range and bearing information relative to said at least one known location outside the zone;

A positioning system movable to the target and adapted a processing system to determine location based upon range and bearing information relative to one of said at least one known reference point location and said at least one known location outside the zone, said positioning system being subject to accumulative errors in determining location;

A processing system to compute the location of said positioning system at the target using said range and bearing information relative to one of said at least one known reference point location and said at least one known location outside the zone to reduce accumulated errors of said positioning system.

9. The system of claim 8 comprising a sensor to determine said at least one known location outside the zone.

10. The system of claim 9 in which said sensor comprises a satellite position receiver.

11. The system of claim 9 in which said positioning system comprises at least one of an IMU and an EDM.

12. The system of claim 11 in which said positioning system comprises an IMU mounted on a survey pole.

13. The system of claim 12 in which said positioning system comprises an EDM mounted on said survey pole.

14. The system of claim 13 in which a satellite position receiver is mounted on said survey pole.

15. The system of claim 14 in which said satellite position receiver is adapted to determine said at least one known location outside the zone.

16. The system of claim 15 in which said satellite positioning receiver is adapted to determine a plurality of said known locations outside the zone.

17. The system of claim 16 in which said EDM is adapted to determine a plurality of said known reference point locations based upon range and bearing information relative to said at least one known location outside the zone.