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. 03, 2020
Filed:
Oct. 14, 2017
Eung Gi Paek, Germantown, MD (US);
Eung Gi Paek, Germantown, MD (US);
Other;
Abstract
The basic concept of satellite-free time transfer using time reversal (T3R) has been invented and successfully demonstrated over long distance (about 4,000 km) with an accuracy of approximately 200 ns rms. The current invention describes new methods to drastically improve performance up to <10 ns rms—better than the current differential GPS, without satellites. The new method employs the Vernier concept utilizing the unique p-independence property of T3R irrespective of carrier frequencies. Also, a histogram method to automatically filter out extraneous data and allow high accuracy and a new method to extend the timing range of T3R beyond the pulse repetition period by removing ambiguity are proposed. A systematic way to obviate the signal blockage caused by transmit/receive window mismatch, is also proposed. Issues and solutions associated with the ionosphere are proposed, including 24-7 operation in adverse ionospheric conditions, such as the constantly changing ionosphere, multiple hops, static asymmetry, and jamming and spoofing.