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:
Aug. 03, 1999
Filed:
Feb. 19, 1997
Yoshihisa Suwa, Nishio, JP;
Seiji Ishikawa, Aichi-gun, JP;
Tomohiro Yamamoto, Anjou, JP;
Takeshi Ito, Toyota, JP;
Tomio Yasuda, Kariya, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
A positioning system is disclosed in which a rate of change .DELTA..DELTA.f in a Doppler shift .DELTA.f of the radio wave transmitted from a GPS satellite is detected in order to determine whether or not an extraordinary radio wave as caused by a multi-path or the like is being received, and a GPS satellite from which an extraordinary radio wave is received is excluded from a group of GPS satellites which are utilized in a positioning calculation. A difference .DELTA.f between a signal frequency f0 transmitted from a GPS satellite and a signal frequency fR receiver is calculated, and a rate of change .DELTA..DELTA.f in the difference .DELTA.f is also calculated. The position of a receiver is calculated on the basis of information transmitted from a plurality of GPS satellites for which the rate of change .DELTA..DELTA.f is equal to or less than a first threshold value, or .DELTA..DELTA.f.ltoreq.30 Hz/s, and the azimuth of a traveling direction of the receiver is calculated on the basis of information transmitted from a plurality of GPS satellites for which the rate of change .DELTA..DELTA.f is equal to or less than a second smaller threshold value or .DELTA..DELTA.f.ltoreq.15 Hz/s.