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. 23, 1981
Filed:
Apr. 06, 1979
William H Parker, Hurst, TX (US);
Harry T Davidson, Hurst, TX (US);
Del Norte Technology, Inc., Euless, TX (US);
Abstract
A radio locator system uses transceivers located in a mobile and at least two stationary stations. Each stationary station serves as one end of a surveyor's baseline. Therefore, since the transceivers are located at opposite ends of a line having a known length, their broadcast signals provide direct distance measurements of two other lines extending between the individual stationary stations and the mobile unit, thereby cooperating with the known line to complete a trilateralization. Each station in the system is identified by a uniquely encoded stream of pulse bursts, each burst encompassing a wide, preprogrammed change of frequency for eliminating interference between the signals used in the locator system and the signals of other users of the same frequency band. An inversion of the preprogrammed frequency change is used for the return of the ranging system signal in order to substantially eliminate or suppress echo returns to the mobile or interrogator station. The sound of the preprogrammed station identifying frequency changes is sometimes called 'chirping'.