Ventspils Radio Astronomy
In post-cold-war Europe, this is one of very few occasions, where a previously
secret military base has been transformed into a civilian research institute.
The preservation of these radio telescopes, and their conversion to civilian
use, was at times a quite dramatic process: A.Balklavs:
Ventspils
Radiotelescopes: History, Parameters, Possibilities, Baltic
Astronomy 5, 181-186 (1996).
Geographical
location
The telescopes are some 20 km north of the city of Ventspils, Latvia (some
150 km across the Baltic sea from Sweden; opposite northern Gotland.),
some 200 km west from Riga.
When left by the armed forces in 1994, the antennas had no functional
electrical systems, and there was no technical documentation.
Groups from different Latvian institutes (Institute
of Astronomy, Institute of Physical Energetics, Riga
Technical University, and others) spent considerable efforts to experimentally
determine the antenna properties, and then to gradually restore its various
functions. The first movement of the 32meter dish was achieved
in May 1995, and the first test observations of celestial sources followed.
During 1997, optical encoders were installed at both telescope axes, and
a computerized pointing and tracking system was put in operation during
1998, supported by grants from the Latvian
Council of Science, and The
Royal Swedish Academy of Sciences.
Test observations during 1997 of sources such as CasA and TauA at 11 GHz
(2.7 cm wavelength) verified the quality of the antenna surface also for
shorter wavelengths, and it is believed that the 32m antenna will
be usable down to about 1 cm.
Solar observations at 11 GHz: This radio image shows several active regions.
The first observing campaign in very long baseline interferometry
took place in November 1999, as part of the Low-Frequency
VLBI Network, connecting radio telescopes across Europe and Asia.
Mark II electronics were used for measurements at 327 MHz.
Work is currently in progress to put also the smaller 16-m antenna into
operation, with a view towards applications in space communication and
remote-sensing applications.
On the VIRAC site (some 200 m from the 32m antenna), a GPS
receiver is operated, providing data for both geophysics and VLBI experiments.
Absolute gravimetry measurements have also been made.
International
cooperation in radio astronomy
In February 1996, an agreement on cooperation in radio astronomy was signed
in Stockholm, involving The
Royal Swedish Academy of Sciences (KVA),
VIRAC (through the
Latvian Academy of Sciences),
Onsala
Space Observatory in Sweden, and Russian
space science institutes, represented by the KOSMION organization.
The aim was to support the development of VIRAC radio astronomy,
and foster international collaboration, in particular concerning Very Long
Baseline Interferometry (VLBI). A Scientific Advisory Council was set up, charged with establishing programs for the scientific work.
Swedish representatives on this council were Roy Booth (Onsala) and Dainis
Dravins (KVA; chairman).
The first meeting of the VIRAC
Scientific Advisory Council was held in Riga and Ventspils in November
1996, the second in June 1998, the third in April 2000, and the
fourth in May 2002, involving
participation from Latvia, Sweden, Russia, Estonia, and the Netherlands..
In July 2001, Ventspils University College
and VIRAC hosted "Radio
Universe", The 2001 Nordic-Baltic Summer School in Radio Astronomy,
an intensive two-week course for some 30 graduate students from the
Nordic-Baltic region, involving 18 lecturers and instructors from also
elsewhere in Europe. Besides lectures and exercises at Ventspils
College, all students made observations of the Sun at 2.7 cm (11 GHz)
using the 32-meter VIRAC antenna, and presented their analyses at the
end of the course.
European collaboration in radio astronomy:
Comments are welcome to dainis@astro.lu.se
Updated JD 2,455,775
