Kurkiaska at midnight

'Tis Friday again (what, already?!), so it is time to end the week with a nice photo. Today's is from the Kurkiaska hydro-power station, on the Kitinen river, just south of Tähtelä, where the institute is. We took this photograph on our way back from the EISCAT_3D Users' Meeting. As we flew in on the late flight, it meant it was really quite late when we crossed the river... just before midnight in fact. The sun had set (just!) but there was still a blaze of colour on the northern horizon.

Have a nice weekend!

Midnight sunset from Kurkiaska. (Photo: D. McKay-Bukowski)

The Kiruna Demonstrator Array

As we wrote earlier, we went to Kiruna last week as part of the planning for the demonstrator array work. The Kiruna EISCAT Demonstrator Array is a phased array of 48 Yagi antennas, arranged in either a 4×12 grid or 4×6 grid... depending on he configuration. It operates at VHF frequencies and is capable of detecting signals from the VHF transmitter in Tromsø.The demonstrator array was mainly built to be an experimental test bed for the digital receivers and digital beam steering that was proposed in the EISCAT_3D design study. Part of the work that the KAIRA team is carrying out is related to this work.

Curious engineers inspect one of the equipment
cabinets. (Photo: D. McKay-Bukowski)

The view along the array. Note the signal cables run
along the frame. (Photo: D. McKay-Bukowski)

Another view (in the sunshine!). But there is still a bit
of snow on the ground. (Photo: D. McKay-Bukowski)

Ionospheric Scintillation with KAIRA and LOFAR

Yesterday we had a seminar from one of our visiting scientists. The subject was ionospheric scintillation and the speaker was Richard Fallows from ASTRON, Netherlands. The abstract of the presentation was:

 The wide bandwidth of KAIRA (Kilpisjärvi Atmospheric Imaging Receiver Array) and LOFAR (Low Frequency Array) is opening up new perspectives in the study of ionospheric scintillation. Direct observing at station level has enabled observations which combine low-band and high-band modes to cover the full available frequency bandwidth from 10 to 250 MHz. For the first time, the evolution of scintillation from weak to strong scattering regimes has been directly observed in dynamic spectra. "Scintillation arcs", seen previously in two-dimensional power spectra from interstellar scintillation observations, have been noted for the first time using observations of ionospheric scintillation. This offers new methods of studying the plasma structures giving rise to the scintillation.

It was an excellent talk... really interesting, great results and a lively discussion afterwards. Thanks Richard!

Thomas Ulich (standing) introduces the speaker
Richard Fallows (right). Photo: E. Turunen.

That also prompted us to investigate some of the riometry data that we had taken and look at some of the scintillation effects that we see in that. It was certainly good to examine some of the data with an expert at hand to advise us on what we were seeing.

Lappish crisps

Only in Lapland...

Actually, these are really, really good. I'd rank them as my third-favourite flavour ever.  (After Paprika and Salt-&-Vinegar, in case you are wondering.)

Kiruna EISCAT site

Today we just have a photograph from the EISCAT radar receiver site at Kiruna, Sweden. (I used to live here once.)

EISCAT Mottagarstasjon, Kiruna. (Photo: D. McKay-Bukowski)

You're breaking up...

At the end of last week a couple of the KAIRA team went over the the EISCAT site at Kiruna, Sweden. The purpose of the visit was to do a preliminary investigation of the set-up of the EISCAT_3D demonstrator array that is built there. We have a few photographs to share, and they will be posted later this week.

However on  the way there, we crossed a few rivers. As it is now well into spring these are starting to melt and break up. At one crossing, there was a huge jumble of broken ice. It looked quite striking... and quite treacherous too!

Broken ice in the river. (Photo: D. McKay-Bukowski)

And the bridge itself. (Photo: D. McKay-Bukowski)

Data recovery

Some of the data that we take with KAIRA can be exported across a 3G mobile data link. However, some experiments generate such large volumes of data that the only sensible thing to do at this stage si to physically go to the site, copy the data off onto harddrives and then bring them back to the institute.

Data computers used to recover some of our experiment data.

The photo shows a couple of heavy-duty servers which are making copies of some VHF radar data that we took earlier this year.