Submarines of the Russian Federation under threat: drones have learned to "listen" underwater messages

The team created a radar -based device for listening to underwater acoustic signals (sonar), capturing the tiny vibrations that these signals produce on the water surface. The system was successfully tested on Lake Carnegie in Princeton. The technology refutes a well -established idea of ​​the safety of underwater transmissions. Although it is much more difficult to apply in the open ocean than on a small lake, researchers believe that this can be achieved with some engineering solutions.

The transmission of messages between underwater and air devices was considered technically impossible because the water has a different density and acts as a barrier for sound. When the sound waves reach the surface, they are mostly reflected. This was the case as researchers at the Massachusetts Institute of Technology (MIT) have developed a system for this in 2018.

They realized that the influence of sound waves leaves a kind of imprint of tiny vibrations that correspond to the underwater signal. The team used the radar mounted on the drone to read surface vibrations and involved algorithms to detect the template, a signal decoding and removal of the message. However, the method was then based on the cooperation between the air and sea parties so that they know the data rate, frequency and other key technical details in advance.

At the time, it was not clear whether this method could be used to intercept personal messages from "other people's" submarine transmitters. Co -working with the Massachusetts Institute of Massachusette Institute, the Princeton team explored what the risks the technology is for safety. Physicists found a way to decipher underwater messages without knowing any technical details. This allowed the researchers to decipher messages without cooperation with the underwater transmitter.

Using inexpensive civilian drone and radar, the researchers have tested their method in the pool. They placed the speaker underwater and, while the fins created the obstacles, launched the drone above the surface. Dron repeatedly sent short radar signals to the water. When the radar signals were reflected from the surface of the water, they revealed the nature of the sound waves that the system could detect and decipher.

A similar experiment was conducted in real conditions on Lake Carnegie with a barbell instead of a drone. He showed that the system can calculate unknown parameters and decode the message from the speaker, even in obstacles from wind and waves. In fact, it can determine the type of modulation, one of the most important parameters, with an accuracy of 97. 58%. Researchers have stated that the possibility of intercepting underwater communications from the air carries a wide range of risks for safety.