Why do we need special call signs? Who invented them? We will answer these and many other questions in the article. The call sign (PSO, call sign recognition) in radio communication is the identifier that identifies the radio transmitter. As a rule, this is a set of numbers, letters, a musical phrase or a meaningful word sent at the beginning of a communication session and necessary to identify the radio station with the receiving object.
A geomagnetic storm is a sudden disturbance of the Earth's geomagnetic field, which can last from several hours to several days. It arises as a result of the interaction of solar wind flows and the planet's magnetosphere.