| 摘要 |
PURPOSE:To provide a transmitting position specifying system wherein a kidnapped person can be detected. CONSTITUTION:A tarnsmitter 101 is provided with a spread signal transmission means which transmits a spread spectrum signal (a) including a modulated discrimination signal. Receivers 102-1 to 102-n are provided respectively with the following: a reception means which receives the signal (a); a reference spread signal generation means; a correlation means which outputs a correlation signal from the signal (a) and from a reference spread signal; a judgment means which demodulates a discrimination signal, which judges the reception timing of the signal (a) and which decides the reception time; a network communication means; and a received information control means which transmits pieces of received information b1 to bn including the reception time and discrimination data on a transmitter to a reception monitoring means 110 via the network communication means. A reception control device is provided with the following: a transmitting position specifying means which specifies the position of a transmitter from received information received from at least three receivers; and a moving speed and direction computation means which computes a moving speed and a moving direction from a change in the position of the transmitter. |
