J band

ITU Radio Band Numbers 1 2 3 4 5 6 7 8 9 10 11 12 ITU Radio Band Symbols ELF SLF ULF VLF LF MF HF VHF UHF SHF EHF THF NATO Radio bands A B C D E F G H I J K L M IEEE Radar bands HF VHF UHF L S C X Ku K Ka Q V W D

J band can refer to two different regions of the electromagnetic spectrum, in the radio and near-infrared.

Radio

The J band is the range of radio frequencies from 10 GHz to 20 GHz in the electromagnetic spectrum. This is equal to wavelengths between 3 and 1.5 centimetres (1.2 and 0.59 in). The J band is in the SHF range of the radio spectrum.

The J band intersects with the X band and K band of the older classification system. The K_u band is within the J band.

in the United Kingdom, the term "J Band" is also used by the Joint Radio Company to refer to their VHF communications band at 139.5-140.5 and 148-149 MHz used by fuel and power industries.

Infrared astronomy

Atmospheric windows in the infrared. The J band is the transmission window centred on 1.25 micrometres

In infrared astronomy, the J band refers to an atmospheric transmission window centred on 1.25 micrometres (in the near-infrared). Betelgeuse is the brightest near-IR source in the sky with a J band magnitude of -2.99. The next brightest stars in the J band are R Doradus (-2.6), Arcturus (-2.2), and Aldebaran (-2.1). In the J band Sirius is the 9th brightest star.

Uses

The J band is used for satellite communications and radar, the latter being central to aircraft systems and their avionics. Satellite communications systems can be used in conjunction with aircraft to help locate and identify enemy targets or provide a role as a reconnaissance platform for soldiers on the ground.