By utilizing sensor stations that detect the direction of HF band radio waves and regional center stations that operate these sensor stations by remote control via high-speed digital lines, both of which were established in five locations throughout the country, and also by operating regional center stations and Kanto Bureau of Telecommunications main center station by remote control via high-speed digital lines, DEURAS HF locates the source of unlicensed radio waves.
This mechanism is able to measure a frequency band between 300kHz to 30MHz, which ranges from low frequency bands used in navigational support for ships to high frequency bands used in international communications like international broadcasts, and locates unlicensed radio stations as well as sources of jamming.
In the high-frequency band, in particular, DEURAS HF monitors unlicensed radio stations at both the domestic and international level. By doing this, Japan continues to conduct the "international monitoring" that is required as a member of the "international community."
This system has been constructed with the foremost technologies in order to conduct efficient and effective supervision, such as locating the direction of radio waves, even during jamming.