Committee on Radio Astronomy Frequencies

The Committee on Radio Astronomy Frequencies (CRAF) is a committee of the European Science Foundation (ESF).

Frequency band allocated to the Radio Astronomy Service:

ITU-RR allocations (+ footnotes):


200 - 202 GHz:		EARTH EXPLORATION-SATELLITE (passive)
			RADIO ASTRONOMY
			SPACE RESEARCH (passive)
			
			5.340 5.341 5.563A

		
202 - 209 GHz:		EARTH EXPLORATION-SATELLITE (passive)
			RADIO ASTRONOMY
			SPACE RESEARCH (passive)
			
			5.340 5.341 5.563A


209 - 217 GHz:		FIXED
			FIXED-SATELLITE (Earth-to-space)
			MOBILE
			RADIO ASTRONOMY
			
			5.149 5.341

National Arrangements for Radio Astronomy different from ITU-R Radio Regulations:

Astrophysical importance of the band 202 - 209 GHz

This frequency band is used for both spectral line and continuum observations. Among the important spectral lines in this band the lines of Water vapor (H218O) and Sulphur monoxide (SO) with rest frequencies of 203.132 GHz and 206.176 GHz, respectively, should be noted.

See also: mm-Wavelength Astronomy.

Threshold levels of interference detrimental to radio astronomy spectral-line observations:

System Sensitivity (noise fluctuations)Threshold Interference Levels
TemperaturePower Spectral DensityInput PowerPower Flux DensitySpectral Power Flux Density
Single Dish2.43 mK-255 dB(WHz-1)-202 dBW-135 dB(Wm-2)-198 (Wm-2Hz-1)

Threshold levels of interference detrimental to radio astronomy continuum observations:

System Sensitivity (noise fluctuations)Threshold Interference Levels
TemperaturePower Spectral DensityInput PowerPower Flux DensitySpectral Power Flux Density
Single Dish0.038 mK-273 dB(WHz-1)-184 dBW-116 dB(Wm-2)-216 dB(Wm-2Hz-1)

NOTE:

For further details the reader is referred to ITU-R Recommendation RA769. It should, however, be noted that the observed spectral power flux densities are much lower than the harmful interference levels because they are made in the main beam of the radio astronomy antennas whereas the harmful levels correspond to reception in the sidelobes, i.e. the differences are related to the gain of the antennas. The differences can be of the order of 50 to 80 dB W m-2 Hz-1 (see ITU-R "Handbook on Radio Astronomy", 1995/2003, chapter 4).

In Europe, the band 202 - 209 GHz is used by the Radio Astronomy Service in:

Threats to the Radio Astronomy Service:

Last modified: March 16, 2005