Satellite radio signal tracking method for GPS receivers
US4983980A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 6, 1990 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Jul 6, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A vehicle-mounted GPS receiver for positioning and reckoning being capable of tracking satellite signals without serious interruption when passing through a dead zone such as a tunnel by quick recapturing of satellite signals after the vehicle has cleared the dead zone, wherein the GPS receiver determines, by calculation, one GPS satellite which is at the maximum elevation angle among the GPS satellites at the very moment if the satellite signals have interrupted simultaneously over a specified period of time, and starts to track the determined GPS satellite as soon as the vehicle clears the dead zone, whereas the GPS receiver calculates orbital positions of other GPS satellites required for positioning, two dimensional or three dimensional, based on the orbital position of the GPS satellite which is at the highest elevation angle, further, when the GPS receiver has a plurality of receiving channels, a plurality of GPS satellites are assigned, one by one, to the plurality of receiving channels from the highest elevation angle in due order for reducing the time in recapture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.