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:
Mar. 15, 2016
Filed:
Dec. 03, 2012
Hans Gregory Schantz, Huntsville, AL (US);
Robert Edward Depierre, Huntsville, AL (US);
Alfred Hans Unden, Owens Cross Roads, AL (US);
Eric Alexander Richards, Madison, AL (US);
Hans Gregory Schantz, Huntsville, AL (US);
Robert Edward DePierre, Huntsville, AL (US);
Alfred Hans Unden, Owens Cross Roads, AL (US);
Eric Alexander Richards, Madison, AL (US);
Q-Track Corporation, Huntsville, AL (US);
Abstract
A method of near-field electromagnetic ranging and location exploits the long-wavelength, near-field characteristics of low-frequency RF signals like those in the vicinity of the AM broadcast band. These signals are robust against scattering from small objects and only mildly perturbed by the urban landscape including building structures. They are thus amenable to an RF fingerprinting approach exploiting a coarse calibration to capture the behavior of the gradually varying signal characteristics. In embodiments, a method of near-field electromagnetic ranging and location may exploit transmit tags transmitting to an infrastructure of locator-receivers, or locator-receiver tags detecting signals from an infrastructure of fixed transmitter beacons. In still further embodiments, fixed transmitter beacons may be supplemented by uncooperative signals sources including signals-of-opportunity like AM broadcast band signals.