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:
Nov. 23, 1993
Filed:
Jul. 05, 1991
Seiichiro Hirata, Sanda, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
The navigation system using GPS signals from satellites first checks whether or not there are four or more satellites in radio range of the moving body. If so, the position calculation section performs an ordinary three-dimensional positioning operation to provide an accurate fix of the moving body. When the number of satellites within the radio range is three or less, the two-dimensional positioning operation is carried out, which comprises reading the previous altitude data from the altitude storage section; calculating the atmospheric pressure deviation from the atmospheric pressure sensor output as caused by the movement of the body; calculating the altitude deviation from the previous altitude data and the atmospheric pressure deviation; calculating the current altitude from the altitude deviation and the previous altitude data; and then calculating the two-dimensional position data from the GPS signals and the current altitude data. This method produces no errors which would otherwise be caused by changes in the altitude of the moving body but provides accurate two-dimensional fix data of the body.