Method of calibrating a compass heading
US4843865A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 29, 1988 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Feb 29, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C17/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for compensating for pitch and roll misalignment in 3-axis magnetometer-type compasses wherein the magnetometer during factory calibration is subjected to magnetic fields corresponding to at least two different latitudes, and correction coefficients for the measured x and y (or horizontal) magnetic field components are derived from signals derived from the z axis (or vertical) magnetic field sensor. The correction coefficients are permanently stored in the compass to provide a heading corrected for internal pitch and roll misalignment of the magnetometer field measuring elements relative to the true vertical that would normally cause errors in azimuth with changes in latitude. No further correction or misalignment is necessary in the field for compass use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.