SATPS mapping with angle orientation calibrator

• US 5,379,045 A
• Filed: 09/01/1993
• Issued: 01/03/1995
• Est. Priority Date: 09/01/1993
• Status: Expired due to Fees

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Kersey, Steve, Janky, James M., Gilbert, Charles
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US08/115,432
• Time in Patent Office: 489 Days
• Field of Search: 342/357, 342/352
• US Class Current: 342/357.36
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections

Abstract

Mobile system apparatus for accurately determining the location of a designated object, spaced apart from the apparatus, without having to approach the designated object. The invention uses a Satellite Positioning System (SATPS), such as GPS or GLONASS, to determine the SATPS location of a first reference SATPS station, whose location is known with high accuracy, and of a second mobile SATPS station. The second mobile SATPS station uses two SATPS signal antennas, spaced apart a known distance but arbitrarily oriented. SATPS antennas at the first and second SATPS stations each receive SATPS signals from a plurality of SATPS satellites that can be used to determine the location of each antenna. The location of each SATPS antenna may be determined using differential corrections for the location of the first SATPS station antenna. The locations of the two SATPS signal antennas at the second SATPS station define a baseline for purposes of determination angular orientation. This angular orientation information, plus information provided by angle and range readouts for the designated object from a rangefinder positioned adjacent to the second SATPS station, allows determination of the location of the designated object without requiring use of magnetic field-dependent instruments such as magnetic compasses that may be inaccurate when used adjacent to metal structures or sources of intense electromagnetic fields. Another approach uses triangulation of the designated object location from two or more spaced apart known locations of the second SATPS station and does not require angular orientation information. Information on the location of the designated object can be processed at the second SATPS station, at the first SATPS station, or at any other place that has SATPS signal processing equipment.

Claims

1. Apparatus for accurately determining the location of a designated object from a position spaced apart from the object, without requiring that the object be approached, the apparatus comprising:

a first SATPS station whose location is known with high accuracy, the first station comprising;

a first SATPS antenna to receive SATPS signals from a plurality of SATPS satellites;

a first SATPS receiver/processor, connected to the first SATPS antenna, to receive the SATPS signals from the first SATPS antenna, to determine the location of the first SATPS antenna and to determine an SATPS location correction that is the difference between the SATPS-determined location of the first SATPS antenna and the known location for the first SATPS antenna; and

a correction signal transmitter, connected to the first SATPS receiver/processor, to receiver and transmit the SATPS location correction information;

a mobile second SATPS station comprising;

second and third SATPS antennas, positioned a known separation distance d apart, to receive SATPS signals from a plurality of SATPS satellites;

a correction signal receiver, connected to the second SATPS receiver/processor, to receive the SATPS location correction information from the first SATPS station; and

a second SATPS receiver/processor, connected to the second SATPS antenna and to the correction signal receiver, to receive the SATPS signals from the first SATPS antenna, to receive the SATPS location correction information from the correction signal receiver, to determine the location of the second and third SATPS antennas and to correct the SATPS-determined location of at least one of the second and third SATPS antennas, using the SATPS location correction information; and

location determination means, located adjacent to the second or third SATPS antenna, for determining the length of an object vector and the angular orientation of the object vector relative to a selected reference line passing adjacent to the second and third SATPS antennas, where the object vector extends from the location determination means to the designated object.

2. The apparatus of claim 1, wherein said second station is mounted on a vehicle that can be moved along a selected curve or within a selected two-dimensional region.

3. The apparatus of claim 1, wherein said second station is portable and can be carried by a human being along a selected curve or within a selected two-dimensional region.

4. The apparatus of claim 1, wherein said location determination means comprises:

a radar-type gun that may be pointed at an object, that emits an electromagnetic signal that relatively small angular divergence when fired, and that determines the distance R from the radar-type gun to the object approximately by the relation R=c'"'"'Δ

t_r /2, where c'"'"' is the signal propagation velocity in an ambient medium in which the radar-type gun is fired and Δ

t_r is the elapsed time between firing of the radar-type gun receipt of a return signal at the gun; and

angle readout means for determining the angle between said selected reference line and said object vector.

5. The apparatus of claim 1, wherein said location determination means comprises:

an optical, electro-optical or ultrasonic rangefinder having first and second optical objectives that are spaced apart form each other, for determining the distance from said location determination means to said designated object; and

angle readout means for determining the angle between said selected reference line and said object vector and for determining the angle between said selected reference line and a line drawn from each of the first and second optical objectives.

6. The apparatus of claim 1, wherein said SATPS signals are electromagnetic signals with a characteristic wavelength λ

and said separation distance d satisfies the relation d>

λ

.

7. The apparatus of claim 1, wherein said selected reference line passes through at least one of said second and third SATPS antennas.

8. The apparatus of claim 1, wherein said selected reference line passes at a fixed, non-zero angle through a line drawn through said second and third SATPS antennas.

9. The apparatus of claim 1 wherein said reference line passes through at least one of said second and third SATPS antennas.

10. Apparatus for accurately determining the location of a designated object from a position spaced apart from the object, without requiring that the object be approached, the apparatus comprising:

a first SATPS station whose location is known with high accuracy, the first station comprising;

a first SATPS antenna to receive SATPS signals from a plurality of SATPS satellites; and

a first SATPS receiver/processor, connected to the first SATPS antenna, to receive the SATPS signals from the first SATPS antenna, to determine the location of the first SATPS antenna, to determine an SATPS location correction that is the difference between the SATPS-determined location of the first SATPS antenna and the known location for the first SATPS antenna, to receive information on and determine the location of one or more other SATPS signal antennas, and to correct the locations of these other SATPS signal antennas, using the SATPS location correction information for the first SATPS antenna;

a mobile second SATPS station comprising;

second and third SATPS antennas, positioned a known separation distance d apart, to receive SATPS signals from a plurality of SATPS satellites; and

a second SATPS receiver/processor, connected to the second SATPS antenna, to receive the SATPS signals from the second and third SATPS antennas and to store this information; and

location determination means, located adjacent to the second or third SATPS antenna, for determining and storing the length of an object vector and the angular orientation of the object vector relative to a selected reference line defined with reference to a selected second line passing adjacent to the second and third SATPS antennas, where the object vector extends from the location determination means to the designated object.

11. The apparatus of claim 10, wherein said second station is mounted on a vehicle that can be moved along a selected curve or within a selected two-dimensional region.

12. The apparatus of claim 10, wherein said second station is portable and can be carried by a human being along a selected curve or within a selected two-dimensional region.

13. The apparatus of claim 10, wherein said location determination means comprises:

radar-type gun that may be pointed at an object, that emits an electromagnetic signal with relatively small angular divergence when fired, and that determines the distance R from the radar-type gun to the object approximately by the relation R=c'"'"'Δ

t_r /2, where c'"'"' is the signal propagation velocity in an ambient medium in which the radar-type gun is fired and Δ

t_r is the elapsed time between firing of the radar-type gun receipt of a return signal at the gun;

angle readout means for determining the angle between said selected reference line and said object vector.

14. The apparatus of claim 10, wherein said location determination means comprises:

an optical, electro-optical or ultrasonic rangefinder having first and second optical objectives that are spaced apart from each other, for determining the distance from said location determination means to said designated object; and

angle readout means for determining the angle between said selected reference line and said object vector and for determining the angle between said selected reference line and a line drawn from each of the first and second optical objectives.

15. The apparatus of claim 10, wherein said SATPS signals are electromagnetic signals with a characteristic wavelength λ

and said separation distance d satisfies the relation d>

λ

.

16. The apparatus of claim 10, wherein said selected reference line passes through at least one of said second and third SATPS antennas.

17. The apparatus of claim 10, wherein said selected reference line passes at a fixed, non-zero angle through a line drawn through said second and third SATPS antennas.

18. The apparatus of claim 10, wherein said second SATPS station further comprises a location signal transmitter to transmit information on said SATPS locations of said second and third SATPS antennas;

wherein said first SATPS station further comprises a signal receiver, connected to said first SATPS receiver/processor, to receive the information on said SATPS locations of said second and third SATPS antenna transmitted by the location signal transmitter; and

wherein said first SATPS determines and provides correction values for said locations of said second and third SATPS antennas, using said SATPS location correction information for said first SATPS antenna.

19. The apparatus of claim 10, further comprising download means, connectable to said first SATPS receiver/processor, and to at least one of said second SATPS signal receiver/processor and said location determination means, for transferring information on said locations of said second and third SATPS antennas and information on said location of said designated object relative to said location determinations means to said first SATPS receiver/processor.

20. The apparatus of claim 10, wherein said line passing adjacent to said second and third SATPS antennas is oriented at a selected angle relative to a line extending from a point on this line to said designated object.

21. Apparatus for accurately determining the location of a designated object from a position spaced apart from the object, without requiring that the object be approached, the apparatus comprising:

a first SATPS station whose location is known with high accuracy, the first station comprising;

a first SATPS antenna to receive SATPS signals from a plurality of SATPS satellites;

a first SATPS receiver/processor, connected to the first SATPS antenna, to receive the SATPS signals from the first SATPS antenna, to determine the location of the first SATPS antenna and to determine an SATPS location correction that is the difference between the SATPS-determined location of the first SATPS antenna and the known location for the first SATPS antenna; and

a correction signal transmitter, connected to the first SATPS receiver/processor, to receive and transmit the SATPS location correction information;

a mobile second SATPS station comprising;

second and third SATPS antennas, positioned a known separation distance d apart, to receive SATPS signals from a plurality of SATPS satellites;

a correction signal receiver, connected to the second SATPS receiver/processor, to receive the SATPS location correction information from the first SATPS station;

a second SATPS receiver/processor, connected to the second SATPS antenna and to the correction signal receiver, to receive the SATPS signals from the first SATPS antenna, to receive the SATPS location correction information from the correction signal receiver, to determine the location of the second and third SATPS antennas and to correct the SATPS-determined location of at least one of the second and third SATPS antennas, using the SATPS location correction information; and

location determination means, located adjacent to the second or third SATPS antenna, for determining the length of an object vector that extends from the location determination means to the designated object, the location determination means comprising;

a radar-type gun, located adjacent to the second or third SATPS antenna, that may be pointed at an object, that emits an electromagnetic signal with relatively small angular divergence when fired, and the determines the distance R from the radar-type gun to the object approximately by the relation R=c'"'"'Δ

t_r /2, where c'"'"' is the signal propagation velocity in an ambient medium in which the radar-type gun is fired and Δ

t_r is the elapsed time between firing of the radar-type gun receipt of a return signal at the gun; and

triangulation means, connected to the radar-type gun and to the second SATPS receiver/processor, for receiving the distances R measured to the designated object from each of two spaced apart locations of the radar-type gun and information on these two locations and for determining the location of the designated object by triangulation.

22. The apparatus of claim 21, wherein said second station is mounted on a vehicle that can be moved along a selected curve or within a selected two-dimensional region.

23. The apparatus of claim 21, wherein said second station is portable and can be carried by a human being along a selected curve or within a selected two-dimensional region.

24. The apparatus of claim 21, wherein said SATPS signals are electromagnetic signals with a characteristic wavelength λ

and said separation distance d satisfies the relation d>

λ

.

25. The apparatus of claim 21, wherein said line passing through said second and third SATPS antennas is oriented at a selected angle relation to a line extending from a point on this line to said designated object.

26. Apparatus for accurately determining the location of a designated object from a position spaced apart from the object, without requiring that the object be approached, the apparatus comprising:

a first SATPS station whose location is known with high accuracy, the first station comprising;

a first SATPS antenna to receive SATPS signals from a plurality of SATPS satellites; and

a first SATPS receiver/processor, connected to the first SATPS antenna, to receive the SATPS signals from the first SATPS antenna and to determine the location of the first SATPS antenna, to determine an SATPS location correction that is the difference between the SATPS-determined location of the first SATPS antenna and the known location for the first SATPS antenna, to receive information on and determine the location of one or more other SATPS signal antennas, and to correct the locations of these other SATPS signal antennas, using the SATPS location correction information for the first SATPS antenna;

a mobile second SATPS station comprising;

second and third SATPS antennas, positioned a known separation distance d apart, to receive SATPS signals from a plurality of SATPS satellites; and

a second SATPS receiver/processor, connected to the second SATPS antenna, to receive the SATPS signals from the second and third SATPS antennas and to store this information; and

location determination means, located adjacent to the second or third SATPS antenna, for determining the length of an object vector that extends from the location determination means to the designated object, the location determination means comprising;

a radar-type gun, located adjacent to the second or third SATPS antenna, that may be pointed at an object, that emits an electromagnetic signal with relatively small angular divergence when fired, and that determines the distance R from the radar-type gun to the object approximately by the relation R=c'"'"'Δ

t_r /2, where c'"'"' is the signal propagation velocity in an ambient medium in which the radar-type gun is fired and Δ

t_r is the elapsed time between firing of the radar-type gun receipt of a return signal at the gun; and

triangulation means, connected to the radar-type gun and to the second SATPS receiver/processor, for receiving the distances R measured to the designated object from each of two spaced apart locations of the radar-type gun and information on these two locations and for determining the location of the designated object by triangulation.

27. The apparatus of claim 26, wherein said second station is mounted on a vehicle that can be moved along a selected curve or within a selected two-dimensional region.

28. The apparatus of claim 26, wherein said second station is portable and can be carried by a human being along a selected curve or within a selected two-dimensional region.

29. The apparatus of claim 26, wherein said SATPS signals are electromagnetic signals with a characteristic wavelength λ

and said separation distance d satisfies the relation d>

λ

.

30. The apparatus of claim 26, wherein said second SATPS station further comprises a location signal transmitter to transmit information on said SATPS locations of said second and third SATPS antennas;

wherein said first SATPS station further comprises a signal receiver, connected to said first SATPS receiver/processor, to receive the information on said SATPS locations of said second and third SATPS antenna transmitted by the location signal transmitter; and

wherein said first SATPS determines and provides correction values of said locations of said second and third SATPS antennas, using said SATPS location correction information for said first SATPS antenna.

31. The apparatus of claim 26, further comprising download means, connectable to said first SATPS receiver/processor, and to at least one of said second SATPS signal receiver/processor and said location determination means, for transferring information on said locations of said second and third SATPS antennas and information on said location of said designated object relative to said location determinations means to said first SATPS receiver/processor.

32. The apparatus of claim 26, wherein said line passing through said second and third SATPS antennas is oriented at a selected angle relative to a line extending from a point on this line to said designated object.