Background ephemeris download in navigational receivers
US7436357B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2006 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | Nov 20, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/258
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides methods and systems for keeping the ephemeris in a navigational receiver current to achieve fast TTFF without the need for connecting to an aiding network or remote server. In an embodiment, the receiver keeps the ephemeris current by downloading the ephemeris in the background. In the preferred embodiment, the receiver uses a background sleep/wake up process to download current ephemeris with minimal power drain. In this embodiment, the receiver alternates between a sleep mode and a wake up mode. During the wake up mode, the receiver attempts to download current ephemeris. The receiver then goes back to the sleep mode until the next wake up to conserve power. The receiver may wake up from the sleep mode to download the ephemeris when the stored ephemeris is no longer current or the ephemeris broadcasted from a satellite has been updated or based on receiver usage patterns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.