3868565 is referenced by 303 patents and cites 6 patents.

A field (e.g., a magnetic field) which nutates about a pointing vector is used to both track or locate an object in addition to determining the relative orientation of this object. Apparatus for generating such a field includes mutually orthogonal coils and circuitry for supplying an unmodulated carrier, hereafter called DC signal, to one coil and an AC modulated carrier signal, hereafter called AC signal, to at least one (usually two) other coil, such that the maximum intensity vector of a magnetic field produced by the currents in the coils nutates about a mean axis called the pointing vector direction of the field. The generated field is sensed in at least two orthogonal directions at the object to be tracked and whose orientation is to be determined. The sensed signals provide an indication of the direction and orientation of the object relative to the coordinates of the generating means.

Title
Object tracking and orientation determination means, system and process
Application Number
05/383,688
Publication Number
3868565
Application Date
July 30, 1973
Publication Date
February 25, 1975
Inventor
Kuipers Jack
Agent
Price Heneveld Huizenga & Cooper
IPC
G01r 33/02
G01S 01/02
G01S 01/42
G01S 01/00
G01S 01/08
F41G 07/00
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