How does high-frequency (HF) radio communication differ from VHF and UHF communications?

High-frequency (HF) radio communication is characterized by its longer wavelength compared to very high frequency (VHF) and ultra-high frequency (UHF) communications. The wavelength of a radio signal is inversely related to its frequency; lower frequencies correspond to longer wavelengths.

HF frequencies typically range from 3 to 30 MHz, which translates to wavelengths from 10 to 100 meters. This longer wavelength is suitable for various communication methods, including skywave propagation, where signals can reflect off the ionosphere and travel over long distances, making HF ideal for intercontinental communication.

In contrast, VHF and UHF frequencies operate at much shorter wavelengths. For example, VHF ranges from 30 to 300 MHz (1 to 10 meters) and UHF from 300 MHz to 3 GHz (10 cm to 1 m). These shorter wavelengths predominantly support line-of-sight communication, making them more suitable for local or regional communications, such as FM radio and television broadcasts, two-way radios, and other services that do not require long-distance travel of the signal.

The other choices do not accurately reflect the unique characteristics of HF communication. HF does not operate at lower frequencies in the context of communication technology, as it is specifically defined