04849692 is referenced by 330 patents and cites 5 patents.

A device for quantitatively measuring the relative position and orientation of two bodies in the presence of metals via measuring the position and orientation of receiving antennae with respect to transmitting antennae utilizing direct current electromagnetic field signals is hereby disclosed. The transmitting and receiving components of the instant device consist of two or more separate transmitting antennae of known position and orientation with respect to each other. Each transmitting antenna is driven one at a time by a pulsed, direct current signal. The receiving antennae measure the values of transmitted direct current magnetic fields one dimension at a time and those of the Earth's magnetic field as well, one dimension at a time. A computer is used to control circuit elements of the transmitting and receiving elements of the device and likewise functions to convert received signals into position and orientation outputs after having first effected a subtraction out of the overall value of the Earth'magnetic field.

Title
Device for quantitatively measuring the relative position and orientation of two bodies in the presence of metals utilizing direct current magnetic fields
Application Number
6/917389
Publication Number
4849692
Application Date
October 9, 1986
Publication Date
July 18, 1989
Inventor
Ernest B Blood
Burlington
VT, US
Agent
John J Welch Jr
Michael J Bujold
Anthony G M Davis
Assignee
Ascension Technology Corporation
VT, US
IPC
G01S 5/04
G01B 7/14
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