Marine VHF radio
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Marine VHF radio is a worldwide system of two-way radio transceivers on ships and watercraft used for bidirectional voice communication from ship-to-ship, ship-to-shore, and in certain circumstances s
A standard handheld marine VHF, mandatory on larger seagoing vessels under the GMDSS rules
A VHF set and a VHF channel 70 DSC set, the DSC on top
A vintage (76–89) marine VHF radiotelephone
Line-of-sight propagation
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Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves can only travel in a direct visual path from the source to the receiver withou
Marine VHF radio
…known as channels. Channel 16 (156.8 MHz) is the international calling and distress channel. Transmission power ranges between 1 and 25 watts, giving a maximum range of up to about 60 nautical miles (111 km) between aerials mounted on tall ships and hills, and 5 nautical miles (9 km; 6 mi) between aerials mounted…
R is the radius of the Earth, h is the height of the transmitter (exaggerated), d is the line of sight distance
R is the radius of the Earth, h is the height of the ground station, H is the height of the air station d is the line of sight distance