Patent ID: 8872889

Claim:
A method for synchronizing a three-dimensional measurement device (3DM) having an internal 3D coordinate system O 3DM , X 3DM , Y 3DM , and Z 3DM , with an intelligent guidance device (IGD) separate from the 3DM, the IGD having a display device, a gravity direction measurement device, an electronic compass, and an internal 3D coordinate system O IGD , X IGD , Y IGD , Z IGD , the method comprising: defining a coordinate system O IGD-Earth , X IGD-Earth , Y IGD-Earth , Z IGD-Earth using a direction opposite to gravity as Z IGD-Earth and a direction corresponding to a magnetic north pole as Y IGD-Earth , from a perspective of the IGD by: measuring a direction of gravity using the gravity direction measurement device and defining a vector Z IGD-Earth as opposite to the direction of gravity; measuring a direction of North magnetic pole using the electronic compass and defining a vector Y IGD-Earth pointing in the North magnetic pole direction; and computing a vector product of Y IGD-Earth and Z IGD-Earth defining vector X IGD-Earth ; computing and applying a rigid transformation T IGD-To-IGDEarth to transform O IGD , X IGD , Y IGD , Z IGD to O IGD-Earth , X IGD-Earth , Y IGD-Earth , Z IGD-Earth ; defining a coordinate system O 3DM-Earth , X 3DM-Earth , Y 3DM-Earth , Z 3DM-Earth using a direction opposite to gravity as Z 3DM-Earth and the direction corresponding to the magnetic north pole as Y 3DM-Earth , from a perspective of the 3DM; and computing and applying a rigid transformation T 3DM-To-3DMEarth to transform O 3DM , X 3DM , Y 3DM , and Z 3DM to O 3DM-Earth , X 3DM-Earth , Y 3DM-Earth , Z 3DM - Earth , such that X IGD - Earth and X 3DM-Earth are substantially parallel and point in a first direction, Y IGD-Earth and Y 3DM-Earth are substantially parallel and point in a second direction, and Z IGD-Earth and Z 3DM-Earth are substantially parallel and point in a third direction, thereby synchronizing an orientation of the IGD with an orientation of the 3DM.