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. 26, 2002
Filed:
Feb. 23, 1999
Miroslaw Balodis, Garden Grove, CA (US);
Leica Geosystems Inc., Norcross, GA (US);
Abstract
A GLONASS receiver and a corresponding method for its calibration for more precise carrier phase measurements. The receiver includes a conventional receiver channel ( ), having a bandpass filter ( ) for establishing the sampling bandwidth prior to digitizing a plurality of received satellite signals, each having a different frequency. The receiver also includes a calibration channel ( ) in which multiple satellite signals are bandbass filtered (in filter ) at a single intermediate frequency, to avoid errors resulting from group delay variation introduced by passing multiple satellite signals through a common bandpass filter. The calibration channel ( ) downconverts ( ) to the intermediate frequency, bandpass filters ( ), and then upconverts ( ) again. Each satellite signal in turn is processed in this manner by selecting appropriate difference frequencies for downconversion and upconversion. The calibration channel ( ) produces a set of reference carrier phase measurements that can be applied to correct errors in carrier phase measurements generated by the conventional receiver channels ( ).