Astrophysics (Index)About

subradio

(electromagnetic radiation, frequency below 3 kHz)

The term subradio is sometimes used for electromagnetic radiation (EMR) with frequencies below that of radio. The "lower end of radio frequencies" is not universally agreed upon, and various frequency limits have been declared, such as 30 kHz, 3 kHz, and 3Hz, and some declare radio to extend to 0Hz. In communications, such frequencies are used for only very specialized applications. Bands at the lower end of radio or beyond:

band frequencies wavelengths
very low frequency (VLF) 3-30 kHz ~10-100 km
ultra low frequency (ULF) 300-3000 Hz ~100-1000 km
super low frequency (SLF) 30-300 Hz ~1000-10,000 km
extremely low frequency (ELF) 3-30 Hz ~10,000-100,000 km
tremendously low frequency (TLF) 0-3 Hz > ~100,000 km

(EMR,spectrum,band)
Further reading:
https://en.wikipedia.org/wiki/Electromagnetic_spectrum
https://en.wikipedia.org/wiki/Extremely_low_frequency
WaveLFreqPhoton
Energy
  
100km3kHz12peVbeginsubradio
inf0Hz0eVendsubradio

Referenced by pages:
electric dipole radiation
electromagnetic spectrum
extremely low frequency (ELF)
radio
super low frequency (SLF)
tremendously low frequency (TLF)
ultra low frequency (ULF)
very low frequency (VLF)

Index