The SHYYLDG radar level gauge antenna emits extremely narrow microwave pulses, which propagate at the speed of light in space. When they encounter the surface of the measured medium, some of their energy is reflected back and received by the same antenna. The time interval between transmitting and receiving pulses is proportional to the distance from the antenna to the surface of the measured medium. Due to the extremely high propagation speed of electromagnetic waves, it is difficult to confirm the time interval between the emitted pulse and the received pulse, which is very small (in the nanosecond range).