| 摘要 |
PROBLEM TO BE SOLVED: To provide a monitoring system for movable body by use of GPS which can effectively solve the problem of hard-to-receive area. SOLUTION: This monitoring system for movable body comprises a terminal device 10 having a receiving part for receiving a GPS signal containing he positioning information transmitted from the positioning satellites (A, B, C...) of a GPS to calculate the information concerning the present position and a transmission part for transmitting the calculated information concerning the present position to a monitoring station, the device 10 being held on a movable body; and a monitoring station 20 for receiving the information concerning the present position transmitted from the terminal device 20. This position monitoring system further comprises an auxiliary radio station 30 for transmitting an auxiliary radio signal containing the position information for a hard-to- receive area where receipt of the radio waves from the positioning satellites of the GPS is difficult, and the terminal device 10 comprises a means for transmitting the position concerning the position of the hard-to-receive area contained in the auxiliary radio signal received from the auxiliary radio station 30 from the transmission part to the monitoring station 20 instead of the information concerning the present position calculated by the GPS receiving part. |
