| 摘要 |
PROBLEM TO BE SOLVED: To effectively use electric power and save the power by feeding the power to a GPS receiver according to a necessary measurement timing. SOLUTION: A portable speed meter/range finder judges whether the action state of a user is changed or not based on a body movement detecting sensor 102 which generates body movement signals expressing the action of the user and the body movement signals which is inputted from the body movement detecting sensor 102 and, when it is judged that the action state of the user is changed, a power supply of the GPS receiver 101 is turned on, and after the lapse of a prescribed time, the power supply of the GPS receiver 101 is turned off. When the power supply of the GPS receiver is turned on, a plurality of times of moving speed calculation processings are executed using a location measurement results of the GPS receiver 101 to obtain a plurality of moving speed data, the mean movement speed in a prescribed time is calculated from the obtained plurality of moving speed data, and the moving distance is calculated using the calculated latest mean moving speed as the present moving speed. |
