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A diagram of the electromagnetic spectrum, showing various properties across the range of frequencies and wavelengths. The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band.
The other types of electromagnetic waves besides radio waves, infrared, visible light, ultraviolet, X-rays and gamma rays, can also carry information and be used for communication. The wide use of radio waves for telecommunication is mainly due to their desirable propagation properties stemming from their longer wavelength. [24]
Because of the difficulty of building antennas that can radiate such long waves, ELF have been used in only a very few human-made communication systems. ELF waves can penetrate seawater, which makes them useful in communication with submarines, and a few nations have built military ELF transmitters to transmit signals to their submerged ...
2182 kHz is a medium-wave frequency still used for marine emergency communication. Marine VHF radio is used in coastal waters and relatively short-range communication between vessels and to shore stations. Radios are channelized, with different channels used for different purposes; marine Channel 16 is used for calling and emergencies.
Radio waves are more widely used for communication than other electromagnetic waves mainly because of their desirable propagation properties, stemming from their large wavelength. [13] Radio waves have the ability to pass through the atmosphere in any weather, foliage, and through most building materials.
Electromagnetic radiation is commonly referred to as "light", EM, EMR, or electromagnetic waves. [2] The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves of different frequency are called by different names since they have ...
In addition, use of millimeter wave bands for vehicular communication is also emerging as an attractive solution to support (semi-)autonomous vehicular communications. [ 15 ] Shorter wavelengths in this band permit the use of smaller antennas to achieve the same high directivity and high gain as larger ones in lower bands.
The VLF band is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and secure military communication. Since VLF waves can penetrate at least 40 meters (131 ft) into saltwater, they are used for military communication with submarines .