Very low frequency

Very low frequency
Frequency range	3–30 kHz
Wavelength range	100-10 km

A VLF receiving antenna at Palmer Station, Antarctica, operated by Stanford University

Very low frequency or VLF is the ITU designation^[1] for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave as the wavelengths range from one to ten myriameters (an obsolete metric unit equal to 10 kilometers). Due to its limited bandwidth, audio (voice) transmission is highly impractical in this band, and therefore only low data rate coded signals are used. The VLF band is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication. Since VLF waves can penetrate at least 40 meters (131 ft) into saltwater, they are used for military communication with submarines.

^ "Nomenclature of the frequency and wavelength bands used in telemmunications" (PDF). ITU. Rec. ITU-R V.431-7. Archived from the original (PDF) on 31 October 2013. Retrieved 20 February 2013.

[ITU_Nomenclature-1] "Nomenclature of the frequency and wavelength bands used in telemmunications" (PDF). ITU. Rec. ITU-R V.431-7. Archived from the original (PDF) on 31 October 2013. Retrieved 20 February 2013.

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