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):

59.3  -  64    GHz:	FIXED
			INTER-SATELLITE
			MOBILE 5.558
			RADIOLOCATION 5.559
			
			5.138


64    -  65    GHz:	FIXED
			INTER-SATELLITE
			MOBILE except aeronautical mobile
			
			5.547 5.556

			
65    -  66    GHz:	EARTH EXPLORATION-SATELLITE
			SPACE RESEARCH
			INTER-SATELLITE
			FIXED
			MOBILE except aeronautical mobile
			
			5.547


66    -  71    GHz:	MOBILE 5.553 5.558
			MOBILE-SATELLITE
			RADIONAVIGATION
			RADIONAVIGATION-SATELLITE
			INTER-SATELLITE

			5.554

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

Astrophysical importance of the band 64 - 65 GHz

The band 64 - 65 GHz is an important radio astronomy band in the series of continuum bands.

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 Dish3.00 mK-254 dB(WHz-1)-207 dBW-152 dB(Wm-2)-209 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 64 - 65 GHz is not used by the Radio Astronomy Service by terrestrial stations.

Last modified: January 25, 2005