Metsähovi

The Metsähovi radio observatory is the only astronomical radio observatory in Finland. The observatory is a separate institute of the Aalto University School of Electrical Engineering, and it is located in Kirkkonummi, some 30 kilometres west of the Otaniemi campus. Metsähovi’s main instrument is the 14-metre radio telescope, which is used around the clock, every day of the year. Its observational data is used, e.g., for studying active galaxies, the Sun, and the rotation of the Earth.

Telescope 1:

Metsahovi 14m

The Metsähovi 14m telescope

 geographic longitude:  24° 23′ 36″
 geographic latitude:  60° 13′ 05″
 altitude above sea level:  79.2 m
 diameter of the telescope:  14 m
  minimum elevation:  0°

Available observing mode: single dish, Very Long Baseline Interferometry (VLBI).

Frequencies used currently:

Frequency band Observing mode
2.21 – 2.35 GHz VLBI / geo-VLBI
8.15 – 8.65 GHz VLBI / geo-VLBI
21.0 – 22.0 GHz single dish (continuum)
21.98 – 22.48 GHz VLBI
22.4 – 23.4 GHz single dish (continuum)
35.3 – 38.3 GHz single dish (solar, continuum)
40 – 45 GHz VLBI
83.5 – 98 GHz single dish, VLBI

Telescope 2:

Metsähovi operates two instruments for continuous monitoring of the Sun at 50-1500 MHz and 11.2 GHz. The 1.8-metre parabolic telescope is  equipped with a 11.2 GHz receiver with 1 GHz bandwidth. The whole Sun  fits in the beam of the telescope, allowing monitoring of the variation  of the Sun’s total flux. The dish is mounted on an alt-azimuth mount to  allow tracking the Sun all day, year round. Two log-periodic antennas  belonging to the international e-Callisto system are mounted on the  sides of the 1.8-meter dish. The e-Callisto system functions between  50-1500 MHz and continuously gathers data on solar flares and other  phenomena.

The Metsähovi 1.8m telescope

 geographic longitude:  24° 23′ 36″
 geographic latitude:  60° 13′ 05″
 altitude above sea level:  79.2 m
  diameter telescope:  1.8 m

Frequencies used currently:

Frequency band Observing mode
50 – 890 MHz single dish (solar observations)
10.7 -11.7 GHz single dish (solar observations)

Telescope 3:

Metsähovi’s third telescope is for continuous monitoring of the Sun at 5-120 MHz.

The Metsähovi Low-Wavelength-Antenna (LWA)

Frequencies used currently:

Frequency band Observing mode
5 – 120 MHz single dish (solar observations)

Research programs: solar radio astronomy, monitoring of active galactic nuclei, geodetic VLBI.

New receivers under development: MCA (Metsähovi Compact Array) project – four 5.5-metre radio telescopes for continuum, solar, and VLBI purposes. Preliminary frequency range will be between 4 and 8 GHz.