176 Navigation
Glossary
2D/3D GPS reception
The GPS receiver uses signals from satellites to calculate its current
position (the user's position), but to acquire a 3D position at least four
signals are necessary, including altitude. The GPS device may not be
able to acquire signals from four satellites as they are constantly moving
and obstacles may block satellite signals. Although the accuracy
decreases when only three signals ca n be acquired, and altitude data
cannot be sent, the receiver can ca lculate a latitude and longitude GPS
position. Only 2D reception is possible.
Route being navigated
The route currently being navigated. When a destination is set, the
route will be continuously navigate d until the destination is deleted,
you arrive at the destination, or the software is closed. Also see “Route”.
City center
The center of the city/town is not th e geographical center of the city/
town, but a location set by the cartog rapher. In towns and villages, this
is usually the most important intersec tion, while in larger cities it is
selected from multiple important intersections. Color design
The color design used for the map and menu screens differs for daytime
and nighttime. Each design has a diff
erent graphic setting, with 2D and
3D each having colors for roads, bl ocks, seas, and lakes, whilst shadow
changes and shadows are displa yed differently in 3D mode.
Daytime screen and nighttime screen designs for the map and menu
are selected one at a time. The design changes automatically when day
becomes night and night becomes day.
GPS accuracy
Various factors can contribute to a margin of error between the user's
actual position and the position acquired from the GPS device. For
example, signal delays in the iono sphere or reflections from objects
around the GPS equipment, can infl uence the accuracy with which the
GPS device can calculate the user's position.
