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. 17, 2001
Filed:
Dec. 21, 1999
Aaron Weinberg, Potomac, MD (US);
ITT Manufacturing Enterprises, Inc., Wilmington, DE (US);
Abstract
A digital positioning system using digital AM and FM radio stations for use in the environment of a plurality of digital AM and FM (AM/FM) radio stations which comprises a customer service center and a reference station which regularly and passively receives signals from all local digital AM/FM stations and measures variations in key parameters of frequency and wavelength thereof and provides AM/FM correctional data signals corresponding to each AM/FM station frequency and wavelength variation to the customer service center. The customer service center is adapted to provide the AM/FM correctional data signals to each of the digital AM/FM radio stations for insertion into ancillary digital data broadcast from each digital AM/FM radio station. A plurality of mobile receivers in the environment of AM/FM radio stations, each of the mobile receivers receiving and processing three or more digital AM and/or FM signals and estimating and updating its position at periodic intervals and sending the results thereof to the customer service center via cellular or other network.