The project, Wireless Electromagnetic Method (WEM), has taken 13 years to build, and is now ready to transmit, Chinese researchers stated.
Extremely Low Frequency (ELF) radio has wavelengths that are tens of thousands of miles in length, allowing them to penetrate geographic obstacles such as mountain ranges and ocean water. Their main utility is military, as submarines can receive ELF signals without the need to surface and potentially reveal their positions.
ELF radio antennas are huge, measuring dozens of miles They can only send a few characters a minute, and whatever is sent is a one-way message, since submarines cannot mount the equipment needed to send their own ELF waves. China’s WEM facility is five time the size of New York City.
China is one of only four countries develop ELF radio antennas, the others being the United States, Russia, and India.
Communications sent about by ELF transmitting stations can travel great distances. When the Soviet Navy first used its ELF facility, located in the north of Russia near the border of Finland, the waves were detected by a station in Antarctica.
This technology has been surpassed by the United States, and different forms of communication with submarines is now employed. In 1982, a transmitting facility was built by the U.S. Navy in Wisconsin, and was decommissioned in 2004. The purpose of the facility was specifically deep-sea submarine communication.
The location of the transmitter has not yet been disclosed, and no satellite images have been found. Suitable places for ELF transmitters are areas with low ground conductivity. Chinese research journals suggest that it is in the central regions of China, though these areas do not have the low frequency conductivity needed, according to maps from the International Telecommunication Union.
Based on conductivity maps, regions in China that may be more suitable for the transmitter are the eastern range of the Himalayas, areas of the southeast ranging from Hong Kong to Shanghai, and in northeast China, near North Korea.