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. 26, 1994
Filed:
Mar. 24, 1992
James J Hatton, Miller Pl., NY (US);
Saulius Janusas, Seacliff, NY (US);
Grumman Aerospace Corporation, Bethpage, NY (US);
Abstract
A covert communication system uses ultraviolet light rather than radio waves as a medium for communication. Suitable wavelengths are chosen by examining atmospheric penetration, attenuation by clouds, presence of interfering sources, and ease of generation and detection. The transmitted ultraviolet light may contain both voice information and other data, impressed upon the light by frequency or pulse modulation using a Pockels cell light modulator. A corresponding receiver can be arranged as a transponder to determine range by phase angle differences between transmitted and reflected waveforms. By using an appropriate lens, the receiver can also determine the angle of incidence of a detected ultraviolet signal, and therefore the bearing of the transmitter.