Committee on Radio Astronomy Frequencies

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)
National Arrangements for Radio Astronomy different from ITU-R Radio Regulations
Astrophysical importance of the band 2690 - 2700 MHz
Threshold levels of interference detrimental to radio astronomy
Radio Astronomy use of this band in Europe
Threats to the Radio Astronomy Service

ITU-RR allocations (+ footnotes):


2670 - 2690 MHz: 	FIXED 5.409 5.410 5.411
			MOBILE except aeronautical mobile 5.384A
			MOBILE-SATELLITE (Earth-to-space) 5.351A
			Earth Exploration-Satellite (passive)
			Radio Astronomy
			Space Research (passive)
			
			5.149 5.412 5.419 5.420


2690 - 2700 MHz:	EARTH EXPLORATION-SATELLITE (passive)
			RADIO ASTRONOMY
			SPACE RESEARCH (passive)
			
			5.340 5.421 5.422
			
			
2700 - 2900 MHz:	AERONAUTICAL RADIONAVIGATION 5.337
			Radiolocation
			
			5.423 5.424

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

Armenia: no allocation
Austria: allocation of the band 2690 - 2695 MHz to the Fixed Service until 2002 while No. 5.340 is retained for the whole band 2690 - 2700 MHz
Bulgaria: no allocation but No. 5.340 aplies
Byelorussia: no allocation
Estonia: no allocation but No. 5.340 aplies
Liechtenstein: no allocation but No. 5.340 applies
Luxembourg: no allocation
Russian Federation: no allocation

Astrophysical importance of the band 2690 - 2700 MHz

The band 2690.0 - 2700.0 MHz needs to be widened, to a total bandwidth of at least 50 MHz preferably by an improvement of the sharing conditions in the band 2655.0 - 2690.0 MHz, and to be protected from interference by satellite transmissions with assignments in adjacent bands (No. 5.340).

Threshold levels of interference detrimental to radio astronomy continuum observations:

System Sensitivity (noise fluctuations) Threshold Interference Levels
Temperature Power Spectral Density Input Power Power Flux Density Spectral Power Flux Density
Single Dish 0.16 mK -267 dB(WHz^-1) -207 dBW -177 dB(Wm^-2) -247 dB(Wm^-2Hz^-1)
VLBI -204 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 2690 - 2700 MHz is used by the Radio Astronomy Service in:

Threats to the Radio Astronomy Service:

Out-of-band emission from the following services:

Last modified: June 20, 2007

	System Sensitivity (noise fluctuations)		Threshold Interference Levels
	Temperature	Power Spectral Density	Input Power	Power Flux Density	Spectral Power Flux Density
Single Dish	0.16 mK	-267 dB(WHz^-1)	-207 dBW	-177 dB(Wm^-2)	-247 dB(Wm^-2Hz^-1)
VLBI					-204 dB(Wm^-2Hz^-1)