Description of the Onsala 25 m telescope


Onsala 25 m telescope

The 25 m diameter polar mounted decimetre-wave telescope was built in 1963. It is used as a single dish for, e.g., observations of interstellar molecules, but mainly for astronomical VLBI observations of star forming regions, radio stars, and active galactic nuclei.

Position

Latitude 57° 23' 35.0456" N
Longitude 11° 55' 03.9685" E
Elevation 18.01 meters

Receivers

The telescope is equipped with the following receivers:

Frequency range Receiver temperature Receiver type
0.8-1.2 GHz  100 K  HEMT amplifier
1.2-1.8 GHz
 30 K  HEMT amplifier
4.5-5.3 GHz  80 K  FET amplifier
6.0-6.7 GHz  80 K  HEMT mixer

All receivers accept dual polarization. The computer control system (Pegasus) for the 25 m antenna uses the same operating system as the 20 m telescope. Thus, essentially the same program controls both telescopes.

Back-ends

The receiver back-end consists of VLBI receivers and recorders, and a hybrid digital autocorrelation spectrometer with the following characteristics:

Spectrometer Total bandwidth Resolution
ACS   0.05, ..., 6.4, 12.8 MHz
 0.03, ..., 4, 8 kHz 
Last modified: March 14, 2007
Responsible for this page: Magnus Thomasson

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ONSALA SPACE OBSERVATORY - SE-439 92 ONSALA, SWEDEN - TEL: +46 (0)31-772 5500