PURPOSE: To provide an electronic monitoring system for monitoring extremely many inmates admitted to facilities.
CONSTITUTION: The respective inmates wear a transmitter for broadcasting RF signals 18 at random time within a prescribed period and a reference transmitter 16 arranged at a known place performs correction so as to consider a local transmission deviation and a system deviation. Transmission signals 18 include common codes and codes intrinsic to the individual transmitter 12. Plural receivers 22 arranged at the known places receive the signals 18. By using relative call termination time of the signals 18 of the inmate transmitter 14 and the reference transmitter in the plural receivers 22, the position of the transmitter 14 is judged. The transmitter 14 can also broadcast intermittent acoustic signals 15, the signals 15 are detected by a detector 17 on the transmitter 16 and the transmitter 16 transmits the RF signals 18 with a tag for indicating that the signals 15 are received. This system 10 supplies updated inmate population and position every second.
JIYON EDOWAADO BIYORUNHORUTO
FUIRITSUPU JIYON BOIRU
HIYUU ROBAATO MAROON
