J band

NATO J band

Frequency range	10 – 20 GHz
Wavelength range	3 – 1.5 cm
Related bands	X / Ku / K bands (IEEE) SHF (ITU)

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

NATO J band

The NATO J band is the obsolete designation given to the radio frequencies from 10 to 20 GHz (equivalent to wavelengths between 3 and 1.5 cm) during the cold war period. Since 1992 frequency allocations, allotment and assignments are in line to NATO Joint Civil/Military Frequency Agreement (NJFA).^[1] However, in order to identify military radio spectrum requirements, e.g. for crises management planning, training, Electronic warfare activities, or in military operations, this system is still in use.

NATO Radio spectrum designation
LATEST SYSTEM			ALTERNATIVE SYSTEM
BAND	FREQUENCY (MHz)		BAND	FREQUENCY (MHz)
A	0–250		I	100–150
B	250–500		G	150–225
C	500 – 1 000		P	225–390
D	1 000 – 2 000		L	390 – 1 550
E	2 000 – 3 000		S	1 550 – 3 900
F	3 000 – 4 000		C	3 900 – 6 200
G	4 000 – 6 000		X	6 200 – 10 900
H	6 000 – 8 000		K	10 900 – 36 000
I	8 000 – 10 000		Ku	10 900 – 20 000
J	10 000 – 20 000		Ka	20 000 – 36 000
K	20 000 – 40 000		Q	36 000 – 46 000
L	40 000 – 60 000		V	46 000 – 56 000
M	60 000 – 100 000		W	56 000 – 100 000

JRC

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.^[2]

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.^[3] The next brightest stars in the J band are Antares (−2.7), R Doradus (−2.6), Arcturus (−2.2), and Aldebaran (−2.1).^[4] In the J band Sirius is the 9th brightest star.

References

1. NATO Joint Civil/Military Frequency Agreement (NJFA)
2. Joint Radio Company
3. R. Cutri and M. Skrutskie (2009-09-07). "Very Bright Stars in the 2MASS Point Source Catalog (PSC)". The Two Micron All Sky Survey at IPAC. Retrieved 2011-12-28.
4. "Simbad object query:Jmag<-2 & Vmag>-9". SIMBAD Astronomical Database. Retrieved 2012-08-22.