To perform appropriate processing even when a user who has just bought a portable device or who is different from a user usually using the device starts to use the device in a room from the beginning.
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. When the correlation has not been recorded and the reception state of the GPS radio waves does not satisfy the predetermined reference, the body vibration frequency is displayed by the MCU 30.
Yashiro Hitoshi
Taro Takahashi