INS Kattabomman is the designation of the VLF-transmission facility of the Indian Navy situated at Vijayanarayanam near Tirunelveli in Tamil Nadu. The facility spread over 3,000 acres has 13 masts, which are arranged in two rings around the central mast. The centre mast has a height of 301 metres, the masts on the inner ring measure 276.4 metres, that on the outer ring measure 227.4 metres.
INS Kattabomman, VLF transmitting station of Indian Navy
One of the Antennas at INS Kattabomman.
Extremely low frequency (ELF) is the ITU designation for electromagnetic radiation with frequencies from 3 to 30 Hz, and corresponding wavelengths of 100,000 to 10,000 kilometers, respectively. In atmospheric science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower-frequency electromagnetic oscillations are considered to lie in the ULF range, which is thus also defined differently from the ITU radio bands.
1982 aerial view of the U.S. Navy Clam Lake, Wisconsin, ELF transmitter facility, used to communicate with deeply submerged submarines. The rights of way of the two perpendicular 14 mile (23 km) overhead transmission lines that constituted the ground dipole antenna which radiated the ELF waves can be seen at lower left.
