Very low frequency

From Wikinfo

Very low frequency or VLF refers to radio frequencies (RF) in the range of 3 to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals are used, such as for radionavigation. Because VLF can penetrate water to a depth of 20 meters (66 feet), they are used to communicate with submarines near the surface. (ELF is used for fully submerged vessels.)

Many natural radio emissions, such as whistlers, can be also heard in this band.

Additional work on this article is appreciated.Template:Radio spectrum

References

• Adapted from the Wikipedia article, "Very_low_frequency" http://en.wikipedia.org/wiki/Very_low_frequency, used under the GNU Free Documentation License