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):


265 -  275 GHz:		FIXED
			FIXED-SATELLITE (Earth-to-space)
			MOBILE
			RADIO ASTRONOMY
			
			S5.149 5.563A


275 - 1000 GHz:		(Not allocated) 5.565

Astrophysical importance of the band 275 - 1000 GHz

This frequency range is used for both spectral line and continuum observations.

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 Dish~2.40 mK~-255 dB(WHz-1)~-201 dBW~-131 dB(Wm-2)~-195 -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 Dish~0.038 mK~-273 dB(WHz-1)~-183 dBW~-113 dB(Wm-2)~-213 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 275 - 1000 GHz is used by the Radio Astronomy Service in:

Threats to the Radio Astronomy Service:

Last modified: January 25, 2005