With increasing importance being placed on environmental protection relevant to radio wave use, more efficient and effective means of radio-wave monitoring is needed to prevent and strengthen controls on a rising number of unlicensed radio stations.
Since FY 1993, the Ministry of Public Ministry of Internal Affairs and Communications has used spectrum user fees to maintain facilities for improvement of radio wave monitoring. As part of such activities, the DEURAS System, a main monitoring system for radio waves which detects unlicensed radio waves, has been developed and is being installed in main cities across Japan. (DEURAS:DEtect Unlicensed RAdio Stations)
The DEURAS system locates unlicensed radio stations by detecting the direction of radio emissions or monitoring radio reception at mobile or stationary sensor stations by way of remote control from the center stations of regional telecommunications bureaus (including the Okinawa Office of Posts and Telecommunications).
The DEURAS System is capable of highly advanced functions compared with conventional systems in terms of precision measurement and operability. The System functions as a 24-hour automatic radio-wave monitoring "facility."
DEURAS Systems are classified into the following:
|-DEURAS Direction finder||DEURAS-D|
|-DEURAS HF direction finder||DEURAS-H|
These are being introduced nationwide.