Integrated terrestrial survey and satellite positioning system

• US 5,471,218 A
• Filed: 07/01/1993
• Issued: 11/28/1995
• Est. Priority Date: 07/01/1993
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Nichols, Mark, Talbot, Nicholas C.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US08/086,665
• Time in Patent Office: 880 Days
• Field of Search: 342/357, 342/352, 342/386, 342/125, 342/58, 342/457, 342/56, 342/458, 364/449, 364/560, 364/460
• US Class Current: 342/357.36
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G01S 19/485 whereby the further system is an optical system or imaging system

Abstract

Apparatus for measuring surveying parameters, such as distances and angular displacements between survey stations, with improved accuracy. The invention combines a differential satellite positioning system (SATPS), available with positioning systems such as GPS and GLONASS, with electromagnetic measurements of distances and optically encoded angles by a conventional electro-optical survey instrument to provide survey measurements that can be accurate to within a few millimeters in favorable situations. The differential satellite positioning system relies upon carrier phase measurements, after removal of certain phase integer ambiguities associated with carrier phase SATPS signals. The SATPS may be retrofitted within the housing of the conventional electro-optical instrument.

Claims

1. Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:

a first station, having an axis that is locally vertical, that provides a reference for the survey and whose location is known with high accuracy, the first station comprising;

a first Satellite Positioning System (SATPS) antenna and first SATPS receiver/processor, connected together, for receiving SATPS signals from two or more SATPS satellites and for determining the location of the first station according to the SATPS signals, the first SATPS receiver/processor also being adapted for determining a first station location difference, if any, between the known location of the first station and the location of the first station as determined by the SATPS signals;

a first station communications means, connected to the first SATPS receiver/processor, for transmitting or receiving information on station location and on SATPS satellite attributes; and

distance measurement means, whose spatial orientation can be varied arbitrarily, connected to the first SATPS receiver/processor, for transmitting an electromagnetic signal including a selected wavelength, for determining the distance from the first station to a selected object that is spaced apart from the first station by receipt of a return electromagnetic signal from the object, for determining an elevation difference, if any, between the first station and the object, and for determining an angular displacement, if any, between a line drawn from the first station to the object and a selected reference line lying in a plane containing the first station; and

a second station, having an axis that is locally vertical, that is spaced apart from and movable relative to the first station and acts as a mobile measurement unit for the survey, the second station comprising;

a second SATPS antenna and ;

second SATPS receiver/processor, connected together, for receiving SATPS signals from two or more SATPS satellites and for determining the location of the second station according to the SATPS signals;

a second station communications means, connected to the second SATPS receiver/processor, for communicating with the first station communications means and for transmitting or receiving information on station location and satellite attributes as determined by the SATPS satellite signals; and

distance measurement responder means, for receiving the electromagnetic waves transmitted by the distance measurement means and for providing a return electromagnetic signal that is received by the distance measurement means;

where at least one of the first SATPS receiver/processor and the second SATPS receiver/processor uses the first station location difference to correct or increase the accuracy of the SATPS-determined location of the second station.

2. Apparatus according to claim 1, wherein said distance measurement responder means includes at least one electromagnetic wave retro-reflector that receives an electromagnetic wave from said first station and transmits this wave toward said first station in a direction approximately parallel to the direction from which the wave was received from said first station.

3. Apparatus according to claim 1, wherein said first station includes a handle by which said first station can be held and transported, and said first SATPS antenna is positioned in this handle.

4. Apparatus according to claim 1, wherein said second station includes a handle by which said second station can be held and transported, and said second SATPS antenna is positioned in this handle.

5. The apparatus of claim 1, wherein said first SATPS antenna has an axis that is approximately parallel to said first station vertical axis.

6. The apparatus of claim 1, wherein said second SATPS antenna has an axis that is approximately parallel to said second station vertical axis.

7. The apparatus of claim 1, wherein said first station further comprises a data output terminal, connected to at least one of said electronic distance meter or said first SATPS receiver/processor, to provide an output signal containing information on at least one of the following:

(1) said location of said first station, as determined by said SATPS signals;

(2) said known, location of said first station;

(3) said difference between said known location and said SATPS-determined location of said first station;

(4) said distance from said first station to said selected object;

(5) said elevation difference between said first station and said selected object; and

(6) said angular displacement between said selected reference line and said line drawn from said first station to said selected object.

8. The apparatus of claim 1, wherein said second station communications means receives from said first station communications means, information on said first station location difference and uses this received information to correct or increase the accuracy of said SATPS-determined location of said second station.

9. The apparatus of claim 1, wherein said first station communications means receives from said second station communications means, information on said SATPS-determined location of said second station and uses said information on said first station location difference to correct or increase the accuracy of said SATPS-determined location of said second station.

10. The apparatus of claim 1, wherein said SATPS signals received by said first SATPS antenna and receiver/processor and by said second SATPS antenna and receiver/processor are carrier phase signals.

11. Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:

a first station, having an axis that is locally vertical, that provides a reference for the survey and whose location is known with high accuracy, the first station comprising;

a first SATPS measurement subsystem for a Satellite Positioning System for receiving SATPS signals from two or more SATPS satellites and for determining the location of the first station according to the SATPS signals;

a first station measurement subsystem, having a spatial orientation that can be varied arbitrarily and being connected to the first SATPS measurement subsystem, for transmitting an electromagnetic signal including a selected wavelength to a selected object that is spaced apart from the first station, for determining an object distance from the first station to the selected object by receipt of a return electromagnetic signal from the object, for determining an object elevation difference, if any, between the first station and the object, and for determining an angular displacement, if any, between a line drawn between the first station and the object and a selected reference line lying in a plane containing the first station;

a first data processing subsystem, for receiving signals from the first SATPS measurement subsystem and from the first station measurement subsystem, and for determining a first station location difference, if any, between the known location of the first station and the location of the first station as determined by the SATPS satellite signals;

a first station communications subsystem, connected to the first SATPS measurement subsystem, for transmitting information concerning first station location, SATPS satellites attributes, and the first station location difference; and

a first user interface subsystem, for receiving information from the first data processing subsystem, and for displaying the known location of the first station; and

a second station, having an axis that is locally vertical and being spaced apart from and movable relative to the first station, the second station comprising;

a second SATPS measurement subsystem for a Satellite Positioning System, for receiving SATPS signals from two or more SATPS satellites, and for determining the location of the second station according to the SATPS signals;

a second station measurement subsystem, for receiving the electromagnetic signal from the first station measurement subsystem and for providing an electromagnetic return signal to the first station;

a second station communications subsystem for receiving information concerning first station location, SATPS satellites attributes, and the first station location difference from the first station communications subsystem;

a second data processing subsystem for receiving signals from the second SATPS measurement subsystem and from the second station communications subsystem, and for determining a corrected second station location, using the first station location difference and the SATPS-determined second station location; and

a second user interface subsystem for receiving information from the second data processing subsystem, and for displaying corrected location of the second station, which is corrected using the first station location difference.

12. Apparatus according to claim 11, wherein said first station measurement subsystem includes distance measurement means for transmitting said electromagnetic signal, for receiving said return electromagnetic signal, and for determining said object distance and said object elevation difference;

and

wherein said second SATPS measurement subsystem includes distance measurement responder means that includes at least one electromagnetic signal retro-reflector, for receiving an electromagnetic signal from said first station and for reflecting this signal toward said first station in a direction approximately parallel to the direction from which the signal was received from said first station.

13. Apparatus according to claim 11, wherein said first station includes a handle by which said first station can be held and transported, and said first SATPS measurement subsystem includes an SATPS antenna that is positioned in this handle.

14. Apparatus according to claim 11, wherein said second station includes a handle by which said second station can be held and transported, and said second SATPS measurement subsystem includes an SATPS antenna that is positioned in this handle.

15. The apparatus of claim 11, wherein said first SATPS measurement subsystem includes an SATPS antenna having an axis that is approximately parallel to said first station vertical axis.

16. The apparatus of claim 11, wherein said second SATPS measurement subsystem includes an SATPS antenna having an axis that is approximately parallel to said second station vertical axis.

17. The apparatus of claim 11, wherein said SATPS signals received by said first SATPS measurement subsystem and by said second SATPS measurement subsystem are carrier phase signals.

18. Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:

a first station, having an axis that is locally vertical, that provides a reference location for the survey and whose location is known with high accuracy, the first station comprising;

a first SATPS measurement subsystem for a Satellite Positioning System for receiving SATPS signals from two or more SATPS satellites and for determining the location of the first station according to the SATPS signals;

a first station measurement subsystem, having a spatial orientation that can be varied arbitrarily and being connected to the first SATPS measurement subsystem, for transmitting an electromagnetic signal having a selected wavelength to a selected object spaced apart from the first station, for determining an object distance from the first station to the selected object by receipt of a return electromagnetic signal from the object, for determining an object elevation difference, if any, between the first station and the object, and for determining an angular displacement, if any, between a line drawn from the first station to the object and a selected reference line lying in a plane containing the first station;

a first station communications subsystem, connected to the first SATPS measurement subsystem, for receiving information that determines location of an object spaced apart from the first station and for receiving SATPS satellites attributes;

a data processing subsystem for receiving signals from the first SATPS measurement subsystem, from the first station measurement subsystem and from the first communications subsystem, for determining a first station location difference, if any, between the known location of the first station and the location of the first station as determined by the SATPS satellite signals, and for determining a corrected second station location, using the first station location difference; and

a user interface subsystem for receiving information from the first communications subsystem and from the first data processing subsystem, and for displaying at least one of the known location of the first station or the corrected second station location; and

a second station, having an axis that is locally vertical and being spaced apart from and movable relative to the first station, the second station comprising;

a second SATPS measurement subsystem for a Satellite Positioning System for receiving SATPS signals from two or more SATPS satellites and for determining the location of the second station according to the SATPS signals;

a second station measurement subsystem, for receiving the electromagnetic signals of the selected wavelength from the first station measurement subsystem and for providing a return electromagnetic signal to the first station; and

a second station communications subsystem, connected to the second SATPS measurement subsystem, for transmitting information that determines the second station location and SATPS satellites attributes to the first station communications subsystem.

19. Apparatus according to claim 18, wherein said first station measurement subsystem includes distance measurement means for transmitting said electromagnetic signal, for receiving said return electromagnetic signal, and for determining said object distance and said object elevation difference;

and

wherein said second SATPS measurement subsystem includes distance measurement responder means that includes at least one electromagnetic signal retro-reflector for receiving an electromagnetic signal from said first station and for reflecting this signal toward said first station in a direction approximately parallel to the direction frown which the signal was received from said first station.

20. Apparatus according to claim 18, wherein said first station includes a handle by which said first station can be held and transported, and said first SATPS measurement subsystem includes an SATPS antenna that is positioned in this handle.

21. Apparatus according to claim 18, wherein said second station includes a handle by which said second station can be held and transported, and said second SATPS measurement subsystem includes an SATPS antenna that is positioned in this handle.

22. The apparatus of claim 18, wherein said first SATPS measurement subsystem includes an SATPS antenna having an axis that is approximately parallel to said first station vertical axis.

23. The apparatus of claim 18, wherein said second SATPS measurement subsystem includes an SATPS antenna having an axis that is approximately parallel to said second station vertical axis.

24. The apparatus of claim 18, wherein said SATPS signals received by said first SATPS measurement subsystem and by said second SATPS measurement subsystem are carrier phase signals.

25. Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:

a first station, having an axis that is locally vertical and having a first station housing and including distance measurement means, whose spatial orientation can be varied arbitrarily, for transmitting an electromagnetic signal including a selected wavelength, for determining the distance from the first station to a selected object that is spaced apart from the first station by receipt of a return electromagnetic signal from the object, for determining the elevation difference, if any, between the first station and the object, and for determining the angular displacement between a line drawn from the first station to the object and a selected reference line lying in a plane containing the first station;

a first Satellite Positioning System (SATPS) antenna and first SATPS receiver/processor, electrically connected together and connected to the first station, for receiving SATPS signals from two or more SATPS satellites and for determining the location of the first station according to the SATPS signals, the first SATPS receiver/processor also being adapted for determining the difference, if any, between the location, known with high accuracy, of the first SATPS antenna and the location of the first SATPS antenna as determined by the SATPS satellite signals, the first SATPS antenna and first SATPS receiver/processor being retrofitted within and being contained within the first station housing;

a first station communications means, connected to the first SATPS receiver/processor, for transmitting or receiving information on station location and on SATPS satellite attributes;

a second station that is spaced apart from and movable relative to the first station and that acts as a mobile measurement unit for the survey, having an axis that is locally vertical, having a second station housing, and including distance measurement responder means, for receiving the electromagnetic signal transmitted by the distance measurement means and for providing a return electromagnetic signal that is received by the distance measurement means;

a second SATPS antenna and second SATPS receiver/processor, electrically connected together and connected to the second station, for receiving SATPS signals from two or more SATPS satellites and for determining the location of the second station according to the SATPS signals, the second SATPS antenna and second SATPS receiver/processor being retrofitted within and being contained within the second station housing;

a second station communications means, connected to the second SATPS receiver/processor, for communicating with the first station communications antenna and for transmitting or receiving information on station location and satellite attributes as determined by the SATPS satellite signals; and

where at least one of the first SATPS receiver/processor and the second SATPS receiver/processor uses the first station location difference to correct the SATPS-determined location of the second station.

26. Apparatus according to claim 25, wherein said distance measurement responder means includes at least one electromagnetic wave retro-reflector that receives an electromagnetic signal from said first station and reflects this signal toward said first station in a direction approximately parallel to the direction from which the electromagnetic signal was received from said first station.

27. Apparatus according to claim 25, wherein said first station includes a handle by which said first station can be held and transported, and said first SATPS antenna is positioned in this handle.

28. Apparatus according to claim 25, wherein said second station includes a handle by which said second station can be held and transported, and said second SATPS antenna is positioned in this handle.

29. The apparatus of claim 25, wherein said first SATPS antenna has an axis that is approximately parallel to said first station vertical axis.

30. The apparatus of claim 25, wherein said second SATPS antenna has an axis that is approximately parallel to said second station vertical axis.

31. The apparatus of claim 25, wherein said first station further comprises a data output terminal, connected to at least one of said electronic distance meter or said first SATPS receiver/processor, to provide an output signal containing information on at least one of the following:

(1) said location of said first station, as determined by said SATPS signals;

(2) said known location of said first station;

(3) said difference between said known location and said SATPS-determined location of said first station;

(4) said distance from said first station to said selected object;

(5) said elevation difference between said first station and said selected object; and

(6) said angular displacement between said selected reference line and said line drawn from said first station to said selected object.

32. The apparatus of claim 25, wherein said SATPS signals received by said first SATPS antenna and receiver/processor and by said second SATPS antenna and receiver/processor are carrier phase signals.

33. Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:

a first station, having an axis that is locally vertical and that acts as a mobile measurement unit for the survey, the first station comprising;

a first station Satellite Positioning System (SATPS) antenna for receiving SATPS signals from two or more SATPS satellites;

a first station communications means, connected to the first station SATPS antenna, for transmitting SATPS signal information on the first station location to another station; and

distance measurement responder means for receiving an electromagnetic signal transmitted by a distance measurement means and for providing a return electromagnetic signal that is received by the distance measurement means; and

a second station, having an axis that is locally vertical and being spaced apart from the first station, that provides a reference location for the survey and whose location is known with high accuracy, the second station comprising;

a second station communications means, for receiving SATPS information on the first station location that is transmitted by the first station communications means;

a second station Satellite Positioning System (SATPS) antenna and SATPS receiver/processor, connected together and connected to the second communications means, for receiving SATPS signals from two or more SATPS satellites, for determining the locations of the first station and of the second station according to the SATPS signals, the second station SATPS receiver/processor also being adapted for determining a second location difference, if any, between the known location of the second station and the location of the second station as determined by the SATPS satellite signals and for determining a corrected first station location which is corrected using the second station location difference; and

distance measurement means, whose spatial orientation can be varied arbitrarily, connected to the second station SATPS receiver/processor, for transmitting an electromagnetic signal including a selected wavelength and for determining the distance from the second station to the first station by receipt of a return electromagnetic signal from the distance measurement responder means at the first station, for determining the elevation difference, if any, between the first station and the second station, and for determining the angular displacement between a line drawn from the first station to the second station and a selected reference line lying in a plane containing the second station.

34. The apparatus of claim 33, wherein said SATPS signals received by said first and second SATPS antennas are carrier phase signals.

35. The apparatus of claim 33, further comprising a user interface means for receiving information from said second SATPS measurement subsystem and from said data processing subsystem, and for displaying at least one of said known location of said second station or said corrected first station location.

36. Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:

a first station, having an axis that is locally vertical, that acts as a mobile measurement unit for the survey, the first station comprising;

a first SATPS measurement subsystem for a Satellite Positioning System for receiving SATPS signals from two or more SATPS satellites;

a first station measurement subsystem, for receiving an electromagnetic signal from another station and for providing a return electromagnetic signal to the other station; and

a first station communications subsystem, connected to the first SATPS measurement subsystem, for transmitting SATPS information on the first station location to another station; and

a second station, having an axis that is locally vertical and being spaced apart from the first station, that provides a reference measurement unit for the survey and whose location is known with high accuracy, the second station comprising;

a second station communications subsystem, for receiving SATPS signal information frown the first communications subsystem;

a second SATPS measurement subsystem for a Satellite Positioning System, connected to the second station communications subsystem, for receiving SATPS signals from two or more SATPS satellites and for determining the location of the first station and of the second station according to the SATPS signals;

a second station measurement subsystem, having a spatial orientation that can be varied arbitrarily, connected to the second SATPS measurement subsystem, for transmitting electromagnetic waves having a selected wavelength to the first station, for receiving a return electromagnetic signal from the first station, for determining an object distance from the second station to the first station from the return electromagnetic signal, for determining the elevation difference, if any, between the first station and the second station, and for determining the angular displacement between a line drawn from the first station to the second station and a selected reference line lying in a plane containing the second station; and

a data processing subsystem for receiving signals from the second SATPS measurement subsystem and from the second station measurement subsystem, for determining a second station location difference, if any, between the known location of the second station and the location of the second station as determined by the SATPS satellite signals and for determining a corrected first station location, which is corrected using the second station location difference.

37. The apparatus of claim 36, wherein said SATPS signals received by said first and second SATPS measurement subsystems are carrier phase signals.

38. The apparatus of claim 36, further comprising a user interface means for receiving information from said second SATPS measurement subsystem and from said data processing subsystem, and for displaying at least one of said known location of said second station or said corrected first station location.

39. A method for measuring one or more parameters for a survey with improved accuracy, the method comprising the steps of:

providing a first station, having an axis that is locally vertical, that acts as a reference station for the survey and that has a location that is known with high accuracy;

receiving SATPS signals from two or more SATPS satellites at the first station, computing an SATPS-determined location of the first station, and determining the difference between the SATPS-determined location of the first station and the known location of the first station, where the SATPS signals are carrier phase signals that have one or more phase integer ambiguities associated therewith;

transmitting electromagnetic signals from the first station to a selected object that is spaced apart from the first station and receiving return electromagnetic signals from the object;

using the return electromagnetic signals to determine at least one of the distance d from the first station to the object, the elevation difference d_v between the first station and the object, a first angular displacement θ

_v between a line drawn from the first station to the object and a first selected reference line in a horizontal plane containing the first station, and a second angular displacement θ

_h between a line drawn from the first station to the object and a second selected reference line lying in a plane containing the first station;

providing as the selected object a second station, having an axis that is locally vertical, that is spaced apart float the first station and that acts as a mobile measurement unit for the survey;

receiving SATPS signals from two or more SATPS satellites at the second station and using these received SATPS signals to determine an SATPS-determined location of the second station; and

correcting the SATPS-determined location of the second station, based upon the difference between the SATPS-determined location of the first station and the known location of the first station.

40. The method of claim 39, further comprising the step of using at least one of said distance d, said elevation difference d_v, said angular displacement θ

_v and said angular displacement θ

_h to reduce the number of said phase integer ambiguities associated with a solution for said SATPS-determined location of said first station.