Patent ID: RE39102

Claim:
An apparatus for determining the location of at least one point in three dimensional space relative to a three dimensional coordinate system defining said space comprising: at least one emitter of electromagnetic radiation, comprising a radiation dispersing element which emits said radiation in a substantially conical pattern which at least approaches a solid angle of about 180° hemisphere, wherein said radiation emission pattern has a centroid such that it at least closely approximates a point source of said radiation thereby causing said centroid of said electromagnetic radiation to be in a substantially invariant relationship to said emitter of said radiation regardless of the angle from which the centroid of the emitted radiation is viewed; an electromagnetic radiation generator operatively associated with each of said emitters; means for transmitting electromagnetic radiation generated by said generator to said emitter; a plurality of electromagnetic radiation sensors, each of which is adapted to detect at least one electromagnetic ray emitted from at least one of said emitters; a power supply for said electromagnetic radiation generator; where there are a plurality of emitters, means to differentiate electromagnetic radiation emitted by at least two of said emitters; and means for determining the location of said emitter relative to the three dimensional coordinate system; wherein, as a consequence of said emitters emitting electromagnetic radiation at a solid angle of at least approaching 180 ° a hemisphere determining the location of a said emitters with greater accuracy than would have been the accuracy determined had the electromagnetic radiation been generated without said dispersing element.