The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 1989
Filed:
Feb. 29, 1988
John T Fowler, Marblehead, MA (US);
Digicourse, Inc., Harahan, LA (US);
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.