LF, or low frequency, refers to a range of electromagnetic waves with frequencies between 30 kHz and 300 kHz. This range is commonly used for various communication systems, including AM radio broadcasting and maritime communication. LF waves can travel long distances and penetrate through obstacles, making them suitable for certain applications. In addition to communication, LF is also utilized in navigation systems and time signals. For example, LF signals are used in LORAN, a long-range navigation system, and in timekeeping services that synchronize clocks. The ability of LF waves to reflect off the ionosphere allows for extended range and reliability in these applications.