| 摘要 |
PROBLEM TO BE SOLVED: To perform speed calculation without botheration of mounting of a separate sensor and surely and accurately even if used by any user, when incapable of receiving speed information grasped by processing signals from a position information satellite.SOLUTION: A portable device comprises an acceleration sensor 38 capable of detecting acceleration speeds in three axial directions. When GPS radio waves can be received by a GPS module 34, a correlation between a body vibration frequency detected by the acceleration sensor 38 and speed information grasped by processing signals included in the GPS radio waves is recorded in a flash ROM 33 by an MCU 30. When a reception state of the GPS radio waves does not satisfy a predetermined reference, based on the body vibration frequency detected by the acceleration sensor 38 and the correlation recorded in the flash ROM 33, a traveling speed is estimated by the MCU 30. |
