Real time clock apparatus for fast acquisition or GPS signals
US5893044A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for improving the acquisition time of GPS signals includes a GPS receiver (21) and a real-time clock circuit (30). The GPS receiver receives GPS signals including a precise time reference signal for providing a position based upon the location of the GPS receiver. The GPS receiver also includes an internal time base (11) derived from the precise time reference signal. The real-time clock circuit is coupled to the GPS receiver for receiving a first time reference signal from the GPS receiver when the precise time reference signal of the GPS signal is available and for providing a second time reference signal to the GPS receiver when the precise time reference signal of the GPS signal is not available thereby allowing a fast acquisition time of GPS signals when the GPS signals are temporarily interrupted or not yet available.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.