Electromagnetic Spectrum

Discussion

introduction

A good, general sequence to remember is radio waves, microwaves, infrared, light, ultraviolet, x‑rays, gamma rays

table-spectrum.shtml

micropulsations

radio waves

name ITU number frequency wavelength
extremely low frequency (ELF)* 1 (~1001 Hz) 3 30 Hz 100,000 10,000 km
super low frequency (SLF)* 2 (~1002 Hz) 30 300 Hz 10,000 1000 km
ultra low frequency (ULF)* 3 (~1003 Hz) 300 3000 Hz 1000 100 km
very low frequency (VLF) 4 (~1004 Hz) 3 30 kHz 100 10 km
low frequency (LF)** 5 (~1005 Hz) 30 300 kHz 10 1 km
medium frequency (MF)** 6 (~1006 Hz) 300 3000 kHz 1000 100 m
high frequency (HF)** 7 (~1007 Hz) 3 30 MHz 100 10 m
very high frequency (VHF) 8 (~1008 Hz) 30 300 MHz 10 1 m
ultra high frequency (UHF) 9 (~1009 Hz) 300 3000 MHz 1000 100 mm
super high frequency (SHF) 10 (~1010 Hz) 3 30 GHz 100 10 mm
extremely high frequency (EHF) 11 (~1011 Hz) 30 300 GHz 10 1 mm
tremendously high frequency (THF)*** 12 (~1012 Hz) 0.3 3 THz 1 0.1 mm
Radio Frequency Bands
Source: ITU
* The ITU actually assigns the designation ELF to everything below VLF. Thus ELF on the table above is ELF1, SLF is ELF2, and ULF is ELF3.
** The middle bands are sometimes identified by their relative wavelengths. Thus low frequency (LF) is also called long wave (LW), medium frequency (MF) is also called medium wave (MW), and high frequency (HF) is also called short wave (SW).
*** This designation is not official, but I like it. The "t" in tremendous matches the "t" in terahertz (the geometric center of the band), matches the "t" in twelve (1 THz = 1012 Hz), matches the "t" in trillion (1012 is also known as a trillion).
  frequency range (GHz)
band IEEE ITU
L "long" 1 2 1.215
1.525

1.400
1.710

*
S "short" 2 4 2.300
2.500
2.700


2.500
2.690
3.400

*
 
C "compromise" 4 8 3.400
4.500
5.250
5.850



4.200
4.800
5.850
7.075
*
*
 
*
X "crosshair" 8 12 8.500 10.50  
uKu "kurze under" 12 18 10.70
13.40
14.00
15.30



13.25
14.00
14.50
17.30
*
 
*
K "kurze"
(german for short)
18 27 17.70
24.05
24.65


20.20
24.25
24.75
*
 
?
aKa "kurze above" 27 40 27.50
33.40

30.00
36.00
*
 
V   40 75 37.50
47.20
59.00


42.50
50.20
64.00
*
*
?
W   75 110 76.00
92.00

81.00
100.0
?
?
mm "millimeter" 110 310 126.0
144.0
231.0
238.0



142.0
149.0
235.0
248.0
?
?
?
?
Radar Frequency Bands
* Space radiocommunication ? Unconfirmed
Source: IEEE, ITU
frequency range
(GHz)
required bandwith
scatterometer
 
altimeter
 
synthetic aperture
radar
precipitation
radar
cloud profiling
radar
0.432–0.438     6 MHz    
1.215–1.300 5–500 kHz   20–085 MHz    
3.100–3.300   200 MHz 20–200 MHz    
5.250–5.570 5–500 kHz 320 MHz 20–320 MHz    
8.550–8.650 5–500 kHz 100 MHz 20–100 MHz    
9.300–9.900 5–500 kHz 300 MHz 20–600 MHz    
13.25–13.75 5–500 kHz 500 MHz   0.6–14 MHz  
17.20–17.30 5–500 kHz     0.6–14 MHz  
24.05–24.25       0.6–14 MHz  
35.50–36.00 5–500 kHz 500 MHz   0.6–14 MHz  
78.00–79.00         0.3–10 MHz
94.00–94.10         0.3–10 MHz
133.5–134.0         0.3–10 MHz
237.9–238.0         0.3–10 MHz
Earth Exploration-Satellite Services (Active) Reserved Frequencies Source: ITU
frequency range (GHz) notes
1.350 1.400 protected at 15 geographic areas in the US*
1.400 1.427 H (1.420406 GHz)
1.718.8 1722.2 protected at 15 geographic areas in the US*
2.690 2.700  
4.590 4.990 protected at 15 geographic areas in the US*
10.68 10.70  
15.35 15.40  
23.60 24.00 NH3 (23.6946 GHz, 23.7236 GHz, 23.8706 GHz)
31.30 31.50  
31.50 31.80  
48.94 49.04  
50.20 50.40  
52.60 54.25  
86.00 92.00 clouds, oil spills, ice, snow; HCN (88.632 GHz)
100.00 102.00 NO (100.49 GHz)
109.50 111.80 CO (109.782 GHz, 110.201 GHz, 112.35 GHz), O3 (110.8 GHz)
114.25 116.00 CO (115.221 GHz, 115.271 GHz)
148.50 151.50 surface, water vapor, cloud parameters; NO (150.74 GHz)
164.00 167.00 Cloud water, rain, ice; ClO (164.38 GHz, 167.2 GHz)
182.00 185.00 H2O (183.31 GHz), O3 (184.75 GHz)
190.00 191.80 three-dimensional sounding for water vapor
200.00 209.00 NO (200.98 GHz)
226.00 231.50 CN (226.600 GHz, 226.800 GHz), CO (230.538 GHz)
250.00 252.00 NO (250.62 GHz, 51.21 GHz)
Radio Astronomy Service (Passive) Reserved Frequencies
Source: Radiocommunication and Climate Change, Handbook of Frequency Allocations and Spectrum Protection for Scientific Uses
*Hat Creek, CA; Goldstone, CA; Arecibo, PR; Socorro, NM; Green Bank, WV; Pie Town, NM; Kitt Peak, AZ; Los Alamos, NM; Fort Davis, TX; North Liberty, IA; Brewster, WA; Owens Valley, CA; Saint Croix, VI; Mauna Kea, HI; Hancock, NH

infrared (a.k.a. "infrared light")

light (a.k.a."visible light")

ultraviolet (a.k.a. "ultraviolet light")

x‑rays

gamma rays