Showing posts with label Kilpisjärvi. Show all posts
Showing posts with label Kilpisjärvi. Show all posts

Tuesday, 23 December 2014

Christmas is coming ... Kilpisjärvi/KAIRA power failure

We had a bit nervous day with KAIRA operations. KAIRA went silent around 10-11 am (LT). We learned  that this was due to a power line failure ~20 km north of Kaaresuvanto. The reason was a broken power line. Some other structures had failed also. Apparently in that region there has been freezing rain and heavy snowfall. Hence, frost in the power lines and the power failure. Here’s the news in Finnish about the Kilpisjärvi/KAIRA power failure: http://www.iltasanomat.fi/kotimaa/art-1419313726115.html


Finnish Meteorological Institute's Kilpisjärvi observations.
KAIRA came back online a bit after 20:00 LT. Hence, we are rather happy that we do not need to drive up to Kilpisjärvi for maintenance operations in Christmas Eve. It has been really cold in Kilpisjärvi during the last days. Temperature has dropped down to around -30 C. Despite of the ~10 hour power break. KAIRA survived and the operational temperature was 8.30 C when KAIRA came back online.
KAIRA operational temperature
at ~20:20 LT.

One interesting news: 2016 there will be a new 45 kV power transmission line. The current 20 kV line will serve as a back-up line thereafter. Hence, looking forward to an upgraded power service in the near future!

... and Merry Christmas!!




Monday, 15 September 2014

KAIRA Tech Paper

We report that KAIRA tech paper is now online as an early access version at IEEE Transactions on Geoscience and Remote Sensing website. The publication details are:


KAIRA: The Kilpisjärvi Atmospheric Imaging Receiver Array—System Overview and First Results

McKay-Bukowski, D.;  Vierinen, J. ; Virtanen, I.I. ; Fallows, R. ; Postila, M. ; Ulich, T. ; Wucknitz, O. ; Brentjens, M. ;Ebbendorf, N. ; Enell, C-F. ; Gerbers, M. ; Grit, T. ; Gruppen, P. ; Kero, A. ; Iinatti, T. ; Lehtinen, M. ;Meulman, H. ; Norden, M. ; Orispaa, M. ; Raita, T. ; de Reijer, J.P. ; Roininen, L. ; Schoenmakers, A. ;Stuurwold, K. ; Turunen, E.

The Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA) is a dual array of omnidirectional VHF radio antennas located near Kilpisjärvi, Finland. It is operated by the Sodankylä Geophysical Observatory. It makes extensive use of the proven LOFAR antenna and digital signal-processing hardware, and can act as a stand-alone passive receiver, as a receiver for the European Incoherent Scatter (EISCAT) very high frequency (VHF) incoherent scatter radar in Tromsø, or for use in conjunction with other Fenno-Scandinavian VHF experiments. In addition to being a powerful observing instrument in its own right, KAIRA will act as a pathfinder for technologies to be used in the planned EISCAT_3-D phased-array incoherent scatter radar system and participate in very long baseline interferometry experiments. This paper gives an overview of KAIRA, its principal hardware and software components, and its main science objectives. We demonstrate the applicability of the radio astronomy technology to our geoscience application. Furthermore, we present a selection of results from the commissioning phase of this new radio observatory.

Published in:

Geoscience and Remote Sensing, IEEE Transactions on  (Volume:PP ,  Issue: 99 )