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:
Jun. 06, 1989
Filed:
Nov. 14, 1988
Leo B Conner, Jr, Phoenix, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A secure identification system for identifying a potential target in a battlefield environment as being either a friend or a foe is disclosed. An interrogator produces two interrogation pulses, such as laser flashes, aimed at the target and separated from each other by a randomly determined period of time. The target detects the two interrogation pulses, measures elapsed time between the two pulses, and prepares a reply signal for transmission which is controlled by the elapsed time. Frequency, pulse width, and transmission delay parameters are each controlled in a substantially random, but predetermined manner in response to the elapsed time. The interrogator has a receiver and qualifier which receive reply signals and define expected values for the controlled parameters. An indication is provided concerning whether the target represents a friend or a foe based on received reply signals at the interrogator.