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6 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. Whenever the destination is set, the route is active
until you delete it, reach your destination or you quit the software. See also: Route.
Colour theme
Your software comes with different colour themes for daytime or night use of the
map and menu screens. Themes are custom graphic settings and they can have
different colours for streets, blocks or surface waters in 2D and 3D modes, and
they display shades or shadows in different ways in 3D mode.
One daytime scheme and one night scheme is always selected for the map and for
the menus. The software uses them when it switches from day to night and back.
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
The software 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 colours.
In 3D mode, you can see the altitude differences, for example valleys and mountains,
elevated roads, and in selected cities 3D landmarks and 3D buildings are also displayed.
Summary of Contents for IGO430
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