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5 Glossary
2D/3D GPS reception
The GPS receiver uses satellite signals to calculate its (your) position and needs at least four
signals to give a three-dimensional position, including elevation. Because the satellites are
moving and because objects can block the signals, your GPS device might not receive four
signals. If three satellites are available, the receiver can calculate the horizontal GPS position
but the accuracy is lower and the GPS device does not give you elevation data: only 2D
reception is possible.
Active route
The currently navigated route. You can save and load routes in Nextar Navigation System,
but only one route can be active at any given time, and it is always active until you delete it,
reach your destination or you quit Nextar Navigation System. See also: Route.
City Center
The City Center is not the geometric center of the city but an arbitrary point the map creators
have chosen. In towns and villages, it is usually the most important intersection; in larger
cities, it is an important intersection.
GPS accuracy
Several factors have impact on the deviation between your real position and the one given by
the GPS device. For example, signal delay in the ionosphere or reflecting objects near the
GPS device have a different and varying impact on how accurately the GPS device can
calculate your position.
Map
Nextar Navigation System works with digital maps which are not simply the computerised
versions of traditional paper maps. Similarly to the paper road maps, the 2D mode of digital
maps show you streets, roads, and elevation is also shown by colors.
You can use digital maps interactively: you can zoom in and out (increase or decrease the
scale), you can tilt them up and down, and turn them left and right. In GPS-supported
navigation, digital maps facilitate route planning.
North-up map orientation
In North-up mode the map is rotated so its top always faces North. This is the orientation in
2D map view mode and in Overview mode. See also: Track-up map orientation.
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