What are high frequency radio waves used for?

Frequencies immediately below MF are denoted low frequency (LF), while the first band of higher frequencies is known as high frequency (HF). MF is mostly used for AM radio broadcasting, navigational radio beacons, maritime ship-to-shore communication, and transoceanic air traffic control .

The main uses of the high frequency spectrum are: Military and governmental communication systems . Aviation air-to-ground communications. Amateur radio.

Because low frequency waves travel globally, they have practical uses. Long before GPS existed, engineers used low frequency waves broadcast from radio stations to determine location anywhere on the planet . And various navies have been using low frequency waves to communicate with submarines across an entire ocean.