Which frequency range includes 3-30 KHz?

The frequency range of 3-30 KHz is classified within the Very Low Frequency (VLF) range. VLF is known for its ability to penetrate deep into the earth and water, making it particularly useful for communication in submarine operations and for long-range navigation systems.

The VLF range is often employed in applications such as time signals, navigational aids, and communication with submerged submarines due to its effective propagation characteristics in various environments. This capability allows VLF signals to travel vast distances, particularly in the military context involving submarine communications.

In contrast, other frequency ranges such as LF (Low Frequency), MF (Medium Frequency), and HF (High Frequency) operate at different bands. LF generally runs from 30-300 KHz, MF covers 300 KHz to 3 MHz, and HF spans from 3 MHz to 30 MHz. Each of these ranges has specific usage scenarios and characteristics that differentiate them from the VLF range, particularly in terms of frequency and propagation characteristics.