The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 1989
Filed:
Aug. 19, 1988
Leland V Gardner, Buellton, CA (US);
Arthur H Hardy, Santa Barbara, CA (US);
Santa Barbara Research Center, Goleta, CA (US);
Abstract
An improved apparatus is disclosed for reliably and unambiguously sensing the angle of arrival of an electromagnetic radiation beam by a remote source. A sensor assembly 2 receives, through an optical window 22, the incident beam which is directed toward first and second detectors 10, 12 by a gradient beam splitter 24. The beam splitter 24 has a gradient of reference and transmittance deposited along one surface which is correlated to the angle of arrival of the radiation. The first detector 10 and second detector 12 receive a portion of the incident beam energy by reflection and transmission respectively from the beamsplitter 24. The ratio of a difference to a sum of the detector responses to the received energy is thereby also correlated with the angle of arrival. Atmospheric scintillation, which causes shifting concentrations of energy in clusters or 'scintels' within the beam, is compensated by the action of gradient opaque stripes of the beam splitter 24 which divide the beam by a constant factor irrespective of the energy distribution. Thus when the ratio of difference to sum of the responsee to the divided beam by the first and second detector 10, 12 is taken, the correlation with angle of arrival is not affected by the shifting energy.