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:
Sep. 12, 1995
Filed:
Apr. 30, 1993
Len Sheynblat, Belmont, CA (US);
Trimble Navigation Limited, Sunnyvale, CA (US);
Abstract
Method and apparatus for reducing the contributions of receiver noise signal error and multipath signal error from signals received in a Satellite Positioning System (SATPS) from one or more SATPS satellites by formation and appropriate filtering of differences of signals DD that are differences of SATPS signals received by the SATPS receiver/processor. A difference signal DD of code-phase-derived delta range signals and carder-phase-derived delta range signals is formed, and this difference signal is passed through a first statistical processing filter with an associated time constant .tau.1 in the approximate range 50-500 sec, to produce smoothed or filtered signal with the estimated receiver noise error reduced or removed. The difference signal DD is passed through second and third statistical processing filters having associated time constants .tau.2=5-20 sec and .tau.3=50-500 sec, and the difference of the output signals of the second and third statistical processing filters is formed and subtracted from DD to form a new difference signal. This new difference signal is passed through a fourth statistical processing filter with an associated time constant .tau.4=50-500 sec, to produce a smoothed or filtered signal with the estimated multipath signal error and estimated receiver noise error reduced or removed.