Trimble Navigation Limited

Joseph W Fontes

Yiming Jim Yu

Xiaorong Zhi

John O'Boyle, Iii

Sven Dietrich

Aaron Vincent Morton

A generic navigation satellite system (GNSS) signal receiver having a fast time to first fix by calibrating a low power always-on real time clock (RTC). The receiver includes an RTC calibrator having a fraction calculator. The RTC calibrator may also include a time expander. Before the receiver is powered off, the fraction calculator uses the fine resolution of GNSS time for determining a time fraction for RTC time. When the receiver is powered back on, the time expander uses an estimate of RTC time drift during the time that GNSS receiver had power off and the time fraction for calibrating and increasing the resolution of the RTC time for an RTC time tick. A signal navigation processor uses the calibrated RTC time for assisting a first fix with code phase search, integration time periods, resolution of epoch integer and/or location-in-space of GPS satellites.

GNSS time fraction calibration of a real time clock

Fast time to first fix by calibration of a real time clock

A circuit for storing GPS data gathered in the field is described. The stored data is later used to test the ability of GPS processing circuits to handle GPS data containing multipath interference and dropouts.

GPS data recorder and playback system

Growing community of inventors

San Jose, CA, United States of America

Joseph W Fontes