Grasslands Observatory - Essays - Protecting Radio Astronomy

Protecting Radio Astronomy

By Tim Hunter

Introduction – The Radio Spectrum and Its Regulation

The average citizen is familiar with the radio spectrum through enjoyment of AM and FM radio, television, short wave radio, amateur radio, and the use of ancillary items, such as garage door openers, cordless phones, microwave ovens, and wireless computer networks. Radio frequency use is ubiquitous and taken for granted. However, it is not an unlimited or harmless resource that can be used at will.

The radio spectrum encompasses a very wide range of frequencies and wavelengths. For the purposes of this essay, all electromagnetic emissions beyond the infrared portion of the spectrum with wavelengths of 1000 microns (1mm) or longer will be considered part of the radio spectrum. The main portions of the radio spectrum are:

Frequency	Band
10 kHz to 30 kHz	Very Low Frequency (VLF)
30 kHz to 300 kHz	Low Frequency (LF)
300 kHz to 3 MHz	Medium Frequency (MF)
3 MHz to 30 MHz	High Frequency (HF)
30 MHz to 144 MHz 144 MHz to 174 MHz 174 MHz to 328.6 MHz	Very High Frequency (VHF)
328.6 MHz to 450 MHz 450 MHz to 470 MHz 470 MHz to 806 MHz 806 MHz to 960 MHz 960 MHz to 2.3 GHz 2.3 GHz to 2.9 GHz	Ultra High Frequency (UHF)
2.9 GHz to 30 GHz	Super High Frequency (SHF)
30 GHz and above	Extremely High Frequency (EHF)

From http://www.jneuhaus.com/fccindex/spectrum.html by John Neuhaus, WA2JXE