What is the primary purpose of HF frequencies?

The primary purpose of HF frequencies is indeed long-range beyond line-of-sight (BLOS) communications without relying on satellite communications (SATCOM). HF frequencies can propagate over vast distances by bouncing off the ionosphere, allowing for effective communication over long ranges, which is particularly beneficial in military operations where other forms of communication may be compromised or unavailable.

HF radio communications can maintain contact between units that are separated by great distances, making them vital for tactical coordination and information exchange in scenarios where line-of-sight communication is not possible. This characteristic of HF radio makes it a crucial tool for operations in remote or rugged terrains where satellite signals may be weak or absent.

In contrast, while secure voice and data communications are an aspect of HF capabilities, the primary distinction lies in its ability to provide long-range communication without the need for satellites, emphasizing its role in BLOS communication. Additionally, ground-to-ground and ground-to-air communications typically utilize different frequency bands or technologies that do not rely solely on the unique properties of HF.