Subs and planes to communicate
A new miniature radar will allow submarine radars to exchange messages with plane radar systems.
For years, engineers have been frustrated that submarines cannot communicate with planes, but now, scientists from the MIT in the US have found a solution. Submarines emit sonar via sound waves that travel easily through water, whereas planes use radio waves or radar, electromagnetic waves, which function in air. Hence, the surface of the water used to be an impenetrable wall.
The MIT scientists have invented a method, which can “translate” the sonar’s sound waves into signals that can be read by a radar. The idea is to use a radar with wavelengths that are substantially shorter than traditional ones, i.e. a millimetre radar which can register the small ripples on the water that occur, when sound waves from a sonar hit it from beneath. In this way, the scientists use the water surface as a translating link.
In the lab, the message “Hello from under water” was transmitted as digital information from an underwater speaker to a millimetre radar. The scientists also tested the system in a basin, in which they could decode the signals in spite of both acoustic disruption under the water and up to 8-cm-high waves on the surface. The scientists now aim to improve the method, which opens wide perspectives. Biologists can use drones to collect data about temperature and currents from underwater sensors, and it will also be easier to find planes that have wrecked in the ocean.
In the lab, scientists sent a digital message from an underwater loud-speaker to a radar in the air.