US 12,345,547 B2
System and method of directional sensor calibration
Jian-Qun Wu, Kingwood, TX (US); James-Christian F. Ang, Hutto, TX (US); and Lee Jacobo Jose Roitberg, Austin, TX (US)
Assigned to Bench Tree Group, LLC, Georgetown, TX (US)
Filed by Bench Tree Group, LLC, Georgetown, TX (US)
Filed on Apr. 3, 2023, as Appl. No. 18/194,903.
Application 18/194,903 is a continuation of application No. 17/121,032, filed on Dec. 14, 2020, granted, now 11,619,518.
Application 17/121,032 is a continuation of application No. 15/862,198, filed on Jan. 4, 2018, granted, now 10,866,116, issued on Dec. 15, 2020.
Application 15/862,198 is a continuation of application No. 14/991,726, filed on Jan. 8, 2016, granted, now 9,863,785, issued on Jan. 9, 2018.
Application 14/991,726 is a continuation of application No. 14/572,569, filed on Dec. 16, 2014, granted, now 9,250,100, issued on Feb. 2, 2016.
Claims priority of provisional application 61/917,855, filed on Dec. 18, 2013.
Prior Publication US 2023/0349723 A1, Nov. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G01C 25/00 (2006.01); E21B 47/022 (2012.01); G01C 17/38 (2006.01); G01R 35/00 (2006.01)
CPC G01C 25/005 (2013.01) [E21B 47/022 (2013.01); G01C 17/38 (2013.01); G01R 35/005 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A system, comprising:
a tri-axial directional sensor comprising orthonormal accelerometers and orthonormal magnetometers;
a calibration stand for positioning and orienting the tri-axial directional sensor, the calibration stand including a housing configured for rotational movement about an axis such that the tri-axial directional sensor may be rotationally orientated about the axis; and
a computer system communicating with the tri-axial directional sensor at a temperature on the calibration stand, the computer system executing calibration software to:
receive measurements of Earth's magnetic and gravity fields by the tri-axial directional sensor in at least four sensor orientations;
determine rotational misalignments between the orthonormal magnetometers and the orthonormal accelerometers; and
correct the rotational misalignments so that measured magnetic dip angles are substantially constant among the sensor orientations.