Term
| Name four different GNSS constallations |
|
Definition
| GPS (USA), Compass (China), Galileo (Europe) and GLONASS (Russia) |
|
|
Term
|
Definition
| The almanac is a data file that tells the receiever which satellites are closest to the receiever. In effect it is a set of data for each satellite that is used to determine its' approximate location in orbit. |
|
|
Term
|
Definition
| The epehmeris data contains information that precisely locates each satellite at that time.; and it is included in the GNSS downstream data. It is only accurate for a short period of time, and must be refreshed. |
|
|
Term
|
Definition
| European Geostationary Navigation Overlay Service.This is an enhancement to GNSS, using ground based stations with a know position it I spossible to determine small errors on GNSS broadcast data. These small differences are braodcast using EGNOS satellites, and are used by GNSS receievers to provide small corrections to their positioning results. Similar systems are the WAAS in North America and MSAS in Japan and East Asia. |
|
|
