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:
Oct. 28, 2008
Filed:
Oct. 11, 2005
Koutaro Wakamatsu, Iwaki, JP;
Takayuki Watanabe, Iwaki, JP;
Koutaro Wakamatsu, Iwaki, JP;
Takayuki Watanabe, Iwaki, JP;
Alpine Electronics, Inc., Tokyo, JP;
Abstract
A navigation apparatus includes a GPS receiver, an error-circle-radius calculating subunit, and a vehicle-position calculating unit. The GPS receiver receives radio waves transmitted from a plurality of GPS satellites and produces a GPS position. The error-circle-radius calculating subunit detects elevation angles of the plurality of GPS satellites used for calculating the GPS position and a center-of-gravity position of the plurality of GPS satellites, and determines an error range around the GPS position on the basis of the detected elevation angles and the center-of-gravity position. The vehicle-position calculating unit calculates a current position using the GPS position obtained from the GPS receiver and the error range determined by the error-circle-radius calculating subunit.