Apparatus and method for calibrating tilt sensor and compass of sensor device for magnetic orientation

A calibration method for field calibration of a module having at least one of a compass or a tilt sensor, the calibration method comprising:

• rotatably coupling a first longitudinal member to a longitudinal support to be rotatable around a longitudinal support axis of the longitudinal support;
• connecting a second longitudinal member to the first longitudinal member to be rotatable around a second longitudinal member axis relative to the first longitudinal member, and to be rotatable with the first longitudinal member around the longitudinal support axis relative to the longitudinal support, the second longitudinal member axis being perpendicular to the longitudinal support axis;
• rotatably coupling a third longitudinal member to the second longitudinal member to be rotatable around a third longitudinal member axis relative to the second longitudinal member, to be rotatable with the second longitudinal member relative to the first longitudinal member, and to be rotatable with the first longitudinal member around the longitudinal support axis relative to the longitudinal support, the third longitudinal axis being perpendicular to the second longitudinal member axis;
• and
• connecting the module to the third longitudinal member to be rotatable with the third longitudinal member around the third longitudinal member axis relative to the second longitudinal member, to be rotatable with the second longitudinal member relative to the first longitudinal member, and to be rotatable with the first longitudinal member around the longitudinal support axis relative to the longitudinal support.

A calibration apparatus for field calibration of a module having at least one of a compass or a tilt sensor, the calibration apparatus comprising:

• a first longitudinal member extending along and rotatable around a first longitudinal member axis;
• a second longitudinal member extending along a second longitudinal member axis and connected to the first longitudinal member to be rotatable around the second longitudinal member axis relative to the first longitudinal member, the second longitudinal member axis being perpendicular to the first longitudinal member axis;
• a third longitudinal member extending along a third longitudinal member axis and coupled to the second longitudinal member to be rotatable around the third longitudinal member axis relative to the second longitudinal member, the third longitudinal axis being perpendicular to the second longitudinal member axis;
• the module to be attached to the third longitudinal member to be rotatable with the third longitudinal member around the third longitudinal member axis relative to the second longitudinal member;
• and
• means for connecting the first longitudinal member, the second longitudinal member, and the third longitudinal member, to rotate independently the module attached thereto around three vertical axes of the module.