These different propagation paths can make the time lag different for every signal received.
Skywave signals can be detected at distances exceeding 300 kilometres (190 mi) from the transmitting antenna.
Typically, a larger geographic area can be covered by a long-wave broadcast transmitter compared to a medium-wave one.
This is because ground-wave propagation suffers less attenuation due to limited ground conductivity at lower frequencies.
This is called Low Frequency Experimental Radio (Low FER).
The 190–435 k Hz band is used for navigational beacons.