Geomagnetic field direction measuring system

• US 6,336,081 B1
• Filed: 10/08/1999
• Issued: 01/01/2002
• Est. Priority Date: 02/10/1997
• Status: Expired due to Term

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Leica Geosystems AG (Hexagon AB)
• Inventors: Gnepf, Silvio, Ramseier, Ernst
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): DUONG, KHOI H
• Application Number:
  US09/355,760
• Time in Patent Office: 816 Days
• Field of Search: 702/65-66, 702/69, 702/74, 702/67, 702/92, 702/93, 702/108, 702/116, 702/183, 702/150-153, 702/FOR-103, 702/FOR.110, 702/FOR-134, 702/FOR-170, 324/244, 324/350, 324/345, 324/348, 324/323, 324/260, 324/200, 333/57, 333/56, 701/4, 701/1, 701/13, 701/224
• US Class Current: 702/150
• CPC Class Codes: G01C 17/30 Earth-inductor compasses
• CPC Class Codes: G01C 17/38 Testing, calibrating, or compensating of compasses
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G01R 33/022 Measuring gradient

Abstract

An arrangement for measuring the direction of the geomagnetic field {right arrow over (B)}_E, in the proximity of a magnetic jamming device with a magnetic field direction variable as a function of time, which is distinguished by the fact that at least two magnetic field measuring devices are provided, each of which measures all three vector components of the total magnetic field ({right arrow over (B)}₁,{right arrow over (B)}₂), the magnetic field measuring devices have a position, ({right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂) which is invariable as a function of time and is fixed relative to one another and relative to the jamming device, and the measured values can be called up synchronously and can be evaluated according to {right arrow over (B)}_E=({right arrow over (B)}₁+{right arrow over (B)}₂)/2+P·({right arrow over (B)}₁−{right arrow over (B)}₂), P({right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂) describing the geometric position of the magnetic field measuring devices relative to one another and relative to the jamming device.

Claims

1. An arrangement for measuring a direction of a geomagnetic field {right arrow over (B)}_E in a proximity of a magnetic jamming device with a magnetic field direction variable as a function of time, wherein at least two magnetic field measuring devices are provided, each of which is adapted to measure all three vector components of a total magnetic field {right arrow over (B)}₁,{right arrow over (B)}₂, the magnetic field measuring devices having fixed positions {right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂ which are invariable as a function of time relative to one another and relative to the magnetic jamming device, and wherein measured values can be called up synchronously and can be evaluated according to {right arrow over (B)}_E=({right arrow over (B)}₁+{right arrow over (B)}₂)/2P·

({right arrow over (B)}₁−

{right arrow over (B)}₂), P({right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂) describing a geometric position of the magnetic field measuring devices relative to one another and relative to the magnetic jamming device.

2. A method of measuring a direction of a geomagnetic field {right arrow over (B)}_E in a proximity of a magnetic jamming device with a magnetic field direction variable as a function of time, wherein three vector components of a total magnetic field {right arrow over (B)}₁,{right arrow over (B)}₂ are measured synchronously in each case by at least two magnetic field measuring devices arranged in a fixed three-dimensional arrangement relative to one another and relative to the magnetic jamming device, and are evaluated according to {right arrow over (B)}_E=({right arrow over (B)}₁+{right arrow over (B)}₂)/2+P·

({right arrow over (B)}₁−

{right arrow over (B)}₂), P({right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂) being a matrix describing a geometric position of the magnetic field measuring devices relative to one another and relative to the magnetic jamming device.

3. The method as claimed in claim 2, wherein the matrix P is determined from normal construction data.

4. The method as claimed in claim 2, wherein the matrix P is determined by measurement, by keeping a total device in a fixed three-dimensional position and bringing the magnetic jamming device into one or more different states in which the total magnetic field is measured and a system of linear equations for a determination is formed therefrom.

7. The method as claimed in claim 2, wherein the matrix P is determined by measurement, by keeping the magnetic field measuring devices in fixed three-dimensional positions and bringing the magnetic jamming device into one or more different states in which the magnetic field is measured, and forming therefrom a system of linear equations.

5. An arrangement for measuring a direction of a geomagnetic field {right arrow over (B)}_E in a proximity of a magnetic jamming device with a magnetic field direction variable as a function of time, the arrangement comprising:

at least two magnetic field measuring devices, each of which is adapted to measure three vector components of a magnetic field {right arrow over (B)}₁,{right arrow over (B)}₂, the magnetic field measuring devices having fixed positions {right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂ which are invariable as a function of time relative to one another and relative to the magnetic jamming device, and wherein measured values of vector components of the magnetic field can be called up synchronously and can be evaluated by at least one of the magnetic field measuring devices according to {right arrow over (B)}_E=({right arrow over (B)}₁+{right arrow over (B)}₂)/2+P·

({right arrow over (B)}₁−

{right arrow over (B)}₂), wherein P({right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂) describes a geometric position of the magnetic field measuring devices relative to one another and relative to the magnetic jamming device.

6. A method of measuring a direction of a geomagnetic field {right arrow over (B)}_E in a proximity of a magnetic jamming device with a magnetic field direction variable as a function of time, the method comprising:

synchronously measuring three vector components of a magnetic field {right arrow over (B)}₁,{right arrow over (B)}₂ using at least two magnetic field measuring devices arranged in a fixed three-dimensional arrangement relative to one another and relative to the magnetic jamming device; and

evaluating measured vector components of the magnetic field according to {right arrow over (B)}_E=({right arrow over (B)}₁+{right arrow over (B)}₂)/2+P·

({right arrow over (B)}₁−

{right arrow over (B)}₂), P({right arrow over (r)}₀,{right arrow over (r)}₁,{right arrow over (r)}₂) being a matrix describing a geometric position of the magnetic field measuring devices relative to one another and relative to the magnetic jamming device.