GPS satellite signal tracking method for GPS receivers
US5036329A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 28, 1990 |
| Grant date | Jul 30, 1991 |
| Priority date | — |
| Expiry date | Aug 28, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/29
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
When reception of satellite signals is lost, for example, one minute, satellite signals are searched firstly in accordance with a narrow-band search mode by varying a search frequency within a range of Doppler frequency shift estimated by a moving speed of a GPS receiver, for example, .+-.600 Hz for a vehicle-mounted GPS receiver, for a duration which is determined by dividing a capture range (.+-.150 Hz) by a rate of Doppler shift (40 Hz/sec) and, secondly, switching over the search mode from the narrow-band search to a wide-band search if recapturing of the satellite signal is failed through the narrow-band search within the predetermined duration (3 minutes 45 seconds) for recapturing the lost satellite signals, and thereby providing a expeditious two-step search method for decreasing a time required in recapturing the lost satellite signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.