PORTABLE TERMINAL DEVICE, METHOD AND PROGRAM FOR MEASURING ITS ALTITUDE OR THE LIKE, AND RECORDING MEDIUM STORING THE PROGRAM

摘要

PROBLEM TO BE SOLVED: To improve performance in positioning by means artificial satellite radio waves with a small number of satellites capable of receiving satellite waves to shorten positioning time. SOLUTION: A structure for calculating altitude or positioning of a portable terminal device (4) equipped with a communication function calculates a reference atmospheric pressure at an approximate position of the portable terminal device by means of atmospheric pressure information detected at the position of the device or atmospheric pressure information externally acquired by the device and approximate position information, and calculates the altitude of the approximate position of the portable terminal device by means of the reference atmospheric pressure and a detected atmospheric pressure at the position of the device. In addition, positioning information is provided to the portable terminal device based on the altitude and externally acquired positioning information. Such a structure can improve the positioning performance with the small number of satellites capable of receiving the satellite radio waves and shorten the positioning time, and enables simple and highly accurate calculation of the altitude value. COPYRIGHT: (C)2009,JPO&INPIT