System and method of directional sensor calibration
US9863785B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 2016 |
| Grant date | Jan 9, 2018 |
| Priority date | — |
| Expiry date | Jan 8, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R35/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved total field calibration system and method is disclosed for reducing the rotational misalignment between magnetic and gravity sensors in a directional sensing system. A method of calibrating a tri-axial directional sensor that includes orthonormal accelerometers and orthonormal magnetometers is disclosed. The method includes measuring Earth's magnetic and gravity fields with said directional sensor in at least 4 sensor orientations; obtaining at least one reference field value of dip drift of Earth's magnetic field from at least one source independent of said directional sensor corresponding to said orientations; and, determining and applying rotational misalignments between said magnetometers and said accelerometers so that measured magnetic dip drifts are substantially equal to said reference values. The calibration process can be performed without monitoring the declination change during the calibration process. Directional sensing systems can be calibrated accurately during a period when the Earth's magnetic field changes rapidly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.