| 摘要 |
PROBLEM TO BE SOLVED: To make a system graspable the position of a PHS or a portable telephone. SOLUTION: The difference of distance is calculated on the basis of the difference between radio-wave arrival times from a transmitter 104 in two receiving points 101, 102 of receivers A, B. The position of the transmitter 104 is found on hyperbolic lines 105, 106 which have the two receiving points 101, 102 as focuses. Regarding the receiving point 103 of a third receiver C, similar hyperbolic lines 107, 108, 109, 110 are found between the receivers A, B. The point of intersection of the three hyperbolic lines is found. Thereby, the position of the PHS or the portable telephone is grasped. Information on the grasped position can be collated as character information or image information by a personal computer or the portable telephone through the Internet. |
