System and method for magnetometer installation

• US 8,629,777 B2
• Filed: 04/07/2011
• Issued: 01/14/2014
• Est. Priority Date: 04/07/2010
• Status: Active Grant

• Current Assignee: L3Harris Aviation Products, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Avionics Systems Incorporated (L3Harris Technologies, Inc.)
• Inventors: Tramper, William D., DeRosia, Andrew L.
• Primary Examiner(s): Lee, Benjamin C
• Assistant Examiner(s): TANG, SIGMUND N
• Application Number:
  US13/081,770
• Publication Number:
  US 20110248854A1
• Time in Patent Office: 1,013 Days
• Field of Search: 340/600, 333/56, 333/57, 333/61, 702/104, 702/151
• US Class Current: 340/600
• CPC Class Codes: G01C 17/38 Testing, calibrating, or compensating of compasses
• CPC Class Codes: G01R 33/007 Environmental aspects, e.g. temperature variations, radiation, stray fields G01R33/025 takes precedence
• CPC Class Codes: G01R 33/022 Measuring gradient

Abstract

A method and system for determining the suitability of a particular location on a mobile craft for mounting a magnetometer includes positioning a magnetometer in a particular location. The magnetometer including at least one output indicating magnetic measurements made by the magnetometer. A computer is connected to the magnetometer and programmed to monitor the output(s) of the magnetometer. An attempt is made to detect magnetic interference at the mobile craft and a human-perceptible indication is provided if the output(s) of said magnetometer changes by more than a specified amount while attempting to detect magnetic interference.

Claims

1. A method of installing an aftermarket magnetometer at a mobile craft, said method comprising:

determining that a particular location on a mobile craft is substantially free of magnetic interference generated by the craft that would unduly interfere with operation of the aftermarket magnetometer;

said determining including positioning a test magnetometer at a particular location of the mobile craft and sensing a magnetic field with said test magnetometer, said test magnetometer including at least one output indicating magnetic measurements made by said test magnetometer;

connecting a computer to said test magnetometer, said computer programmed to monitor said at least one output;

attempting to detect magnetic interference at the mobile craft with said test magnetometer while said craft remains substantially stationary; and

providing a human perceptible indication if said at least one output of said test magnetometer changes by more than a specified amount.

2. The method of claim 1 wherein said attempting to detect magnetic interference includes operating at least one powered component of the mobile craft while said computer monitors said at least one output.

3. The method of claim 2 wherein said computer monitors said at least one output by calculating a heading corresponding to said magnetic measurements made by said test magnetometer and provides the human-perceptible indication if the heading changes by more than a particular amount.

4. The method of claim 2 including operating a plurality of powered components of the mobile craft while said computer monitors said at least one output;

and

providing the human-perceptible indication if said at least one output of said test magnetometer changes by more than the specified amount while any of said multiple powered components are operated.

5. The method of claim 1 wherein said attempting to detect magnetic interference includes moving said test magnetometer around to a plurality of different locations while said computer monitors said at least one.

6. The method of claim 5 wherein said computer monitors said at least one output by measuring field strength.

7. The method of claim 6 wherein said computer compares the measured field strength with a baseline field strength measured by said test magnetometer prior to said moving.

8. The method of claim 1 wherein said human-perceptible indication comprises at least one chosen from a visual indication and an audio indication.

9. The method of claim 1 wherein said mobile craft is an airplane.

22. The method of claim 1 including using the aftermarket magnetometer as said test magnetometer.

10. A method of installing an aftermarket magnetometer at a mobile craft, said method comprising:

determining that a particular location on a mobile craft is substantially free of magnetic interference generated by the craft that would unduly interfere with the operation of the aftermarket magnetometer;

said determining including mounting a test magnetometer at the particular location of the mobile craft and sensing a magnetic field with said test magnetometer, said test magnetometer including at least one output indicating magnetic measurements made by said magnetometer;

connecting a computer to said test magnetometer, said computer programmed to monitor said at least one output and calculate a heading corresponding to said magnetic measurements made by said test magnetometer;

operating at least one powered component of the mobile craft while said computer monitors said at least one output and while said craft remains substantially stationary; and

providing a human-perceptible indication if said at least one output of said test magnetometer changes by more than a specified amount while said powered component is operated.

11. The method of claim 10 further including:

inputting said specified amount into said computer.

12. The method of claim 10 further including:

operating a plurality of powered components of the mobile craft while said computer monitors said at least one output; and

providing the human-perceptible indication if said at least one output of said magnetometer changes by more than the specified amount while any of said multiple powered components are operated.

13. The method of claim 12 wherein said human perceptible indication comprises at least one chosen from a visual indication and an audio indication.

14. The method of claim 10 wherein said mobile craft is an airplane.

23. The method of claim 10 including using the aftermarket magnetometer as said test magnetometer.

15. An installation system for determining the suitability of a particular location on a mobile craft for mounting an aftermarket magnetometer, said system comprising:

a test magnetometer adapted to be positioned at the mobile craft, said test magnetometer including at least one output indicating magnetic measurements made by said magnetometer;

a computer in communication with said test magnetometer, said computer programmed to monitor said at least one output and to determine that said at least one output has varied by more than a specified amount; and

an indicator that is adapted to provide a human-perceptible indication if said output changes by more than a specified amount while attempting to detect magnetic interference, said indicator comprising at least one chosen from a visual display and an audio indicator.

16. The system of claim 15 wherein said computer is programmed to monitor said at least one output by calculating a heading corresponding to said magnetic measurements made by said magnetometer and provides the human-perceptible indication if the heading changes by more than a particular amount.

17. The system of claim 15 wherein said computer is programmed to monitor said at least one output by measuring field strength.

18. The system of claim 17 wherein said computer is programmed to compare the measured field strength with a baseline field strength measured prior to said moving.

19. An installation system for determining the suitability of a particular location on a mobile craft for mounting an aftermarket magnetometer, said system comprising:

a test magnetometer adapted to be mounted at the particular location at the mobile craft, said test magnetometer including at least one output indicating magnetic measurements made by said test magnetometer;

a computer in communication with said test magnetometer, said computer programmed to display a heading based upon said magnetic measurements made by said test magnetometer, said computer further programmed to monitor changes in said heading while at least one powered component of said mobile craft is operated to determine that said output has changed by more than a specified amount; and

an indicator that is adapted to provide a human-perceptible indication if said heading changes by more than a specified amount while said powered component is operated, said indicator comprising at least one chosen from a visual display that and an audio indicator.

20. The system of claim 19 wherein said computer is programmed to receive said specified amount from an operator.

21. The system of claim 19 further including a magnetometer attitude transmitter that communicates with said computer prior to said magnetometer being mounted in said particular location, said magnetometer attitude transmitter communicating roll and pitch information to said computer.