POLFAR

POLFAR project start-up

At the end of 2013, POLFAR received a grant from the Polish Minister of Science and Higher Education for the construction and equipment of three international LOFAR stations as part of their national research infrastructure investment. The new LOFAR stations will be located in Lazy (in southern Poland, operated by the Jagiellonian University in Krakow), Baldy (in northern Poland, operated by the University of Warmia and Mazury in Olsztyn), and Borowiec (in western Poland, operated by the Space Research Centre of the Polish Academy of Sciences).

The formal agreement between the POLFAR consortium and ASTRON now marks the start of the preparations for the roll-out of these new stations. March 2014, ASTRON and the Polish LOFAR consortium POLFAR signed a contract for the construction of three new antenna stations for the International LOFAR Telescope (ILT).


Astronomical interest POLFAR
Astronomical interests in Poland range from neutral hydrogen distribution in the early universe, to the timing of pulsars and studies of magnetic fields in various intergalactic, interstellar, planetary, and solar environments.

Added performance
The International LOFAR Telescope has 38 stations in the Netherlands, six in Germany, and one each in France, Sweden and the United Kingdom. Connecting the three new POLFAR stations will add valuable extra sensitivity to the array. Moreover, the Polish stations provide new baselines of up to 1550 km in the array, making the ILT a much more capable instrument for high resolution imaging of detailed structures. Finally, the positions of the new stations literally provide new angles on ionospheric tomography.

Documentation, tendering and production hardware
Up to 2014 the roll-out of new stations was done with hardware produced during the first 2007/2008 production run. Since the LOFAR stock was used during the build of many new international stations. For the first time a new production run was needed to build the three Polish stations.

First the documentation needed an update. Some of the electronics could no longer be build due to obsoleteness of components. In these cases a redesign could not be prevented, which also means the new design should undergo the acceptance tests to make sure it would operate according specification.

Secondly the tendering needed to be done in some cases the same companies could be contracted but in many other cases depending on the cost thresholds a tender process was started. For one part a European call was necessary.

Now the manufacture of the thousands of pieces of hardware could be started and tracked to make sure every individual part would be delivered in time at the right station site. In total 36 full truck loads where delivered in Poland.

 

New HBA assembly method
For the first time in the history of LOFAR, all High Band Antennas (HBA) were assembled on-site, and not in a factory. This meant that a large industrial tent was placed at the site locations in which the assembly took place. The assembly and test method varied from the normal procedure because some of the assembly tools could not be used. The preparations and test trails of the new assembly method were done  in the Netherlands before they were carried out in Poland. The reason for this alternative assembly method was to save on the substantial cost of transporting the fully assembled HBA's, by shipping their components in the most compact way. The titanic labour was done mainly by volunteer students of the site universities.


Roll-out

All of the above was carried out under tremendous time pressure because the roll-out of all three stations should take place during the 2015 summer months. Last site to realise was Lazy which is at the base of the Tatra mountain range. The unforgiving winter climate lived up to our expectations when beginning of October the last tiles where place during the first snowfall of the season. All three stations undergone there commissioning tests with flying colours, which concluded the POLFAR project.

Design: Kuenst.    Development: Dripl.    © 2020 ASTRON