Map data are managed by use of map file names representing given areas. In each map file name, the first character denotes a map structure code; the second character represents a zoom level for a zoom-in or zoom-out operation of the map on display; and the...

A topographic modelling system has a raster system to link topographical objects such as feature sides (L1-4) and nodes (N1-6) in a traffic system with the raster index.

A microprocessor obtains a vehicle travelled distance by multiplying the number of pulses by a distance factor R, the number of pulses having been outputted from a vehicle speed sensor and having been counted by a counter, In addition, the microprocessor e...

A route guidance device capable of preventing frequent executions of auto-rerouting in the vicinity of a junction where a current-position skipping of a vehicle due to map-matching is likely to occur. A route guidance unit (132) does not request a route se...

A portable terminal device includes: a position detecting unit (1) for detecting device position on the basis of a GPS signal; an orientation detecting unit (2) for detecting device orientation by means of a flux gate type magnetic sensor (2) or another ge...

The method involves using a database containing a traffic network with linear objects, forming sets of points for an object to be decoded and objects in the network, determining the number of points within a defined range of at least one point in a second ...

A method and system for providing navigation services to portable communications devices, such as cellular phones. A cellular phone user uses a cellular phone to request navigation services. The cellular phone is located in a geographic area that has a cel...