Positional information providing system, navigation system, and terminal device

摘要

A positional information providing system is provided in which positional information including altitude can be highly accurately acquired even though a user is located outdoors or indoors. A system includes a server device including a map data storage unit, an altitude storage unit, a reference position coordinates receiving unit, a reference point altitude information generating unit locating reference position coordinates and reference point altitude, a map data transmitting unit and a reference point altitude information transmitting unit, and a terminal device including a positional information acquiring unit, a reference point information transmitting unit, a reference point altitude information receiving unit, a map data receiving unit and a reference point altitude detecting unit detecting altitude at a reference point. The terminal device includes a calibration unit for the altitude data acquired at the reference point altitude detecting unit and a map display unit displaying map data and altitude data.