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:
Jan. 09, 2018
Filed:
Jan. 08, 2016
Bench Tree Group, Llc, Georgetown, TX (US);
Jian-Qun Wu, Kingwood, TX (US);
James-Christian F. Ang, Hutto, TX (US);
Lee Jacobo Jose Roitberg, Austin, TX (US);
Bench Tree Group, LLC, Georgetown, TX (US);
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.