Monday 30 June 2014

A view to the top of Finland

The highest point in Finland lies near the summit of Halti (Haltitunturi in Finnish; Háldi in Sami), on the Norwegian border in the far north-west of Finland.  At a height of 1324m, it is a spur of the mountain whose main summit lies within Norway.

Getting to it from the Finnish side involves walking or skiing some 50km from the road, a journey which usually starts in the village of Kilpisjärvi.  However, it is more accessible from the Norwegian side, at least in summertime.  On a recent visit to KAIRA in early June, I went to see if it would be possible.

From Kåfjord, a dirt track winds it's way up into the mountains, terminating only a few kilometers from the summit of Halti, on the side of a reservoir.  In the picture the reservoir can be seen, still frozen, in the middle with Halti as the large mountain in the background.  With the snow staying late this year, the road was impassable from about half-way up so getting to the summit of Halti itself was out of reach of a one-day trip and this was as far as I got.

The dog, incidentally, is a seven-year old Labrador and also a regular visitor to KAIRA.

Sunday 29 June 2014


KAIRA is actually closer to Siilasjärvi, rather than Kilpisjärvi, although you are unlikely to find the former on the map and Kilpisjärvi is the name of the nearest town in any case. Between Siilasjärvi and Kilpisjärvi is a small white-water river called Siilasjoki, which drains the former into the second.

There is a small path that runs up to Pikku Malla from about 1 km near the KAIRA site. There is now a new timber bridge that crosses the rive and heads up the mountain.

No other LOFAR site has such picturesque scenery!

Saturday 28 June 2014

June snow banks

During the week just gone, we had some summer workers up at KAIRA to carry out maintenance and other site duties. We had one nice afternoon, so we made the most of it and trekked up a nearby hill to get a nice view of the site. There were a few patches of snow to get through but otherwise the landscape is pretty clear now.

Trudging through the snow in June (Photo: D. McKay-Bukowski)

Friday 27 June 2014

LBA in the summer sun

Today we have just a nice photograph of the LBA aerials. In the background is Pikku Malla.

Have a nice weekend everyone!

Thursday 26 June 2014


The Biological Station has a few smaller outstations where researchers can stay. The small cottage of "Kalela" is one of these. It is located right at the edge of the main Kilpisjärvi Lake, just across from Pikku Malla and within sight of Saana. It is a really idyllic location.

Pikku Malla as seen from Kalela (Photo: D. McKay-Bukowski)

Saana and the Kalela cottage to the right (Photo: D. McKay-Bukowski)

This is where some of our 2014 summer workers stayed during the repair/maintenance trips to KAIRA.

Wednesday 25 June 2014

Anti sea sickness measures

With all the people and equipment in the site office (a.k.a. barracks), we felt it would be wise to put some extra shoring timbers under it. While it probably would not have toppled over, it certainly reduced the amount of vibration and movement in the building (which is a converted railway carriage on road wheels).

Fitting shoring timbers (Photo: D. McKay-Bukowski)

A lot more stable now (Photo: D. McKay-Bukowski)

Tuesday 24 June 2014

Baby mountain hares

We've a few mountain hares about the site, but recently there have been some leverets (= baby hares) at the KAIRA site.

Mountain leveret near the storage container (Photo: D. McKay-Bukowski)

Mountain leveret under the High-Band Antenna array (Photo: J. Keskitalo)

The Finnish word for mountain hare is jänis.  This is also a slang word for someone who is a bit shy and reserved. The Latin scientific name of the mountain hare is Lepus timidus . So as you might imagine, these are not particularly bold creatures and we are lucky to get photographs of them.

Monday 23 June 2014


Once the snow has all gone, there is invariably scraps of winter damage lying around on the site which needs to be cleaned up.

A reflective tab found after the snow melted away.

This work is done every year, along with replacement equipment being installed. Although pleasant, it can still be a harsh environment at times and the attrition on the system is continual.

Saturday 21 June 2014

Midnight solar flare

Around this time of year, we have the midnight sun and one very long day! The midnight sun is nicely viewed from KAIRA and it is always calm and peaceful. Of course that's not always the case at the sun itself.

A few weeks back we caught a solar flare very close to the local solar midnight. Due to the equation of time, the application of daylight-savings/summer time in Europe, and our location, the minimum elevation of the Sun is not exactly at clock midnight.

However, very close to the point of minimum elevation (and the Sun crossing the northen meridian), KAIRA caught this solar flare.

Midnight solar flare! (Image: D. McKay-Bukowski)

Given that the elevation of the sun was quite low (approx. +2 degrees), this must have been a bright flare!

Our northern summer solstice occurs at 10:51 UTC on 21 June 2014.

Friday 20 June 2014

Midnight sun

Today we just have a nice photograph of the midnight sun taken from KAIRA.

Midnight sun seen from KAIRA (Photo: D. McKay-Bukowski)

Wednesday 18 June 2014

Plotting single-station LOFAR data with the R programming language

The R programming language is a free  (GNU Public Licence) language and environment use for scientific computing. It has developed a strong reputation for being used for statistics and data analysis, although its use goes far beyond that. It is easily extensible with function packages and has an active community. Staff at Sodankylä Geophysical Observatory use R, particularly for signal processing and inverse problem methods.

I myself have never used R before; my native language is actually C, with PostScript, Python, FORTRAN as some of the others that I know. I've been aware of R because my colleagues use it, but other than that I've not had a chance to use it. I keep meaning to write something, but those opportunities rarely come up and, when they do, it is usually faster to hack something out in a language I know.

But a couple of days ago an good opportunity presented itself, so here's my first real programme beyond the "Hello world!".

Lassi has asked for some KAIRA data, in particular some beamlet statistics data. These are the data generated by any LOFAR single station. Not only did he want the data, but also a way to plot it... using R (which is what he uses). Fair enough. So here's my attempt:

R-code to plot a single beamlet from a LOFAR beamlet statistics (BST) file.

   # Set the name of the file that we wish to read
   filename = "20131220_150320_bst_00X.dat"

   # Set the beamlet number we wish to plot
   beamlet = 243

   # Create a connection to this file
   file = file(filename,"rb")

   # Typical maximum file size (244 beamlets x 86400 seconds/day)
   maxsize = 244 * 86400

   # Read the entire file as a raw data stream (up to maxsize)
   raw = readBin(file,double(),size=8,n=maxsize,endian="little")

   # Re-shape the data into matrix w/ 244 columns (beamlets)
   data = matrix(raw,ncol=244,byrow=TRUE)

   # Convert the data into a dB scale
   data_db = 10.0*log10(data)

   # Create an array of sample numbers for the X-axis
   sample_num = array(1:dim(data_db)[1])

   # Plot the data (we need "beamlet+1"; R counts from 1, not 0)
        xlab="Samples since file start time",
        ylab=expression("ADUs 10log"[10]),
        main=paste("KAIRA   ",filename,"   Beamlet=",beamlet) )

The plot looks like this:

I also plotted the same thing with KPB (KAIRA Plot Beamlet-statistcs). KPB is the python software that we normally use for plotting things.

For those curious, the command line settings for this were:

   %  kpb --db -y 243 20131220_150320_bst_00X.dat -g trace \
          -t "KAIRA   %n   bl=243" -o kpb_example.png

Of course I will continue to use Python and C code, as that is what I do. However, hopefully the above code fragment will help anyone either learning R or getting started with LOFAR single-station data.

Bear in mind that I am a novice though! So, if you're an R-expert and have suggestions on how I could improve that code, or make it more R-esque, do let us know in the comments below!


Tuesday 17 June 2014

Saana transmitter

Sticking up from the southern peak of Saana is the local transmitter tower. Mobile communications base station and FM radio transmitter (though probably not the source of our mysterious "dragon teeth" interference problem.) Joona took this photograph from just down the road near the Biological Station.

Saana and the transmitter tower (Photo: J. Keskitalo)

Monday 16 June 2014


Today's photograph is the long road (called Käsivarrentie) that runs though this part of the world, coming up from the direction of Karesuvanto, through Kilpisjärvi village and continuing on to KAIRA (and, if you insist, you can keep going into Norway and on to Tromsø.

Käsivarrentie (Photo: Joona Keskitalo)

Sunday 15 June 2014

KAIRA EISCAT VHF intersection heights/elevations

In order for the KAIRA beam to intersect the vertical EISCAT VHF transmitter beam, the elevation must be set as follows.  (All data provided by I.I.Virtanen, U. Oulu).

Note that the azimuth to the EISCAT VHF is 313.95 degrees. The numbers for the above plots are as follows. Hgt is the height above the EISCAT VHF transmitter in kilometres and Elev is the require elevation of observation from KAIRA to have the beam centre at this height.

Hgt Elev Hgt Elev Hgt Elev
0 -0.735 670 82.155 1340 85.69
10 6.101 680 82.259 1350 85.717
20 12.747 690 82.359 1360 85.743
30 19.044 700 82.457 1370 85.768
40 24.881 710 82.552 1380 85.793
50 30.199 720 82.644 1390 85.818
60 34.987 730 82.734 1400 85.843
70 39.261 740 82.821 1410 85.867
80 43.06 750 82.906 1420 85.891
90 46.431 760 82.989 1430 85.914
100 49.423 770 83.07 1440 85.937
110 52.082 780 83.148 1450 85.96
120 54.451 790 83.225 1460 85.982
130 56.568 800 83.3 1470 86.005
140 58.467 810 83.373 1480 86.027
150 60.176 820 83.444 1490 86.048
160 61.719 830 83.513 1500 86.069
170 63.117 840 83.581 1510 86.09
180 64.39 850 83.648 1520 86.111
190 65.551 860 83.712 1530 86.132
200 66.613 870 83.776 1540 86.152
210 67.589 880 83.837 1550 86.172
220 68.488 890 83.898 1560 86.192
230 69.318 900 83.957 1570 86.211
240 70.087 910 84.015 1580 86.23
250 70.801 920 84.072 1590 86.249
260 71.465 930 84.127 1600 86.268
270 72.084 940 84.181 1610 86.287
280 72.663 950 84.234 1620 86.305
290 73.205 960 84.286 1630 86.323
300 73.714 970 84.337 1640 86.341
310 74.192 980 84.387 1650 86.358
320 74.642 990 84.436 1660 86.376
330 75.067 1000 84.484 1670 86.393
340 75.468 1010 84.531 1680 86.41
350 75.847 1020 84.577 1690 86.427
360 76.207 1030 84.622 1700 86.443
370 76.548 1040 84.667 1710 86.46
380 76.872 1050 84.71 1720 86.476
390 77.18 1060 84.753 1730 86.492
400 77.473 1070 84.795 1740 86.508
410 77.752 1080 84.836 1750 86.523
420 78.019 1090 84.876 1760 86.539
430 78.274 1100 84.916 1770 86.554
440 78.518 1110 84.955 1780 86.569
450 78.751 1120 84.993 1790 86.584
460 78.974 1130 85.031 1800 86.599
470 79.188 1140 85.067 1810 86.614
480 79.394 1150 85.104 1820 86.628
490 79.591 1160 85.139 1830 86.643
500 79.781 1170 85.174 1840 86.657
510 79.963 1180 85.209 1850 86.671
520 80.139 1190 85.243 1860 86.685
530 80.308 1200 85.276 1870 86.698
540 80.471 1210 85.309 1880 86.712
550 80.628 1220 85.341 1890 86.725
560 80.78 1230 85.373 1900 86.739
570 80.927 1240 85.404 1910 86.752
580 81.068 1250 85.435 1920 86.765
590 81.205 1260 85.465 1930 86.778
600 81.337 1270 85.495 1940 86.79
610 81.466 1280 85.524 1950 86.803
620 81.59 1290 85.553 1960 86.815
630 81.71 1300 85.581 1970 86.828
640 81.826 1310 85.609 1980 86.84
650 81.939 1320 85.636 1990 86.852
660 82.049 1330 85.664 2000 86.864

We hope you read all these numbers and memorised them!

Saturday 14 June 2014


Recently, we reported on the arrival of a new computer. This `canister mac' has now been installed in the RF-container at KAIRA and is being used for data acquisition. In addition to the computer itself there are two RAID arrays of 28 TB each, which triples the existing capacity of the in-container storage.

The new canister mac (`kaira05') atop the LOFAR
local control unit. (Photo: D. McKay-Bukowski)

The form factor of this machine is difficult so I would not recommend this. Also, the use of MacOSX has been problematic, so we may yet install Linux on this. However these are the tools we've been given and, with a lot of effort, we have managed to get it working at least for the basics. (High-speed processing remains to be tackled).

Friday 13 June 2014


On the evening of 02-Jun-2014, I spotted a spectacular pair of parhelia (sun dogs) over the KAIRA LBA array. This is the first time I've seen two of them so bright and distinct -- normally one tends to dominate. Furthermore, the entire arc could be seen, including the enhanced region of brightness at the top.

Parhelia over the KAIRA LBA array. (Photo: D. McKay-Bukowski)

Thursday 12 June 2014

The KAIRA refrigerator

You need to keep things cold. So here, even in summer, we simply leave things outside. The local KAIRA refrigerator is just patches of ice out and about the site.

Keeping the drinks cool along the
north-western edge of the HBA array.

Of course this really only works in summer. In winter this is actually a deep freezer and the milk, juice, etc., would be frozen solid!

Wednesday 11 June 2014

Update on the POLFAR project

As we reported last year after the Polish announcement, three new antenna stations for International LOFAR Telescope are to be constructed in Poland. 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. Today we have the press release from ASTRON regarding the announcement.

Today the contract was signed for the POLFAR construction work. Specifically, the Netherlands Institute for Radio Astronomy (ASTRON) and the Polish LOFAR consortium (POLFAR) signed a contract for the construction of three new antenna stations for the International LOFAR Telescope (ILT) in the north, west and south of Poland. The signing of the contract took place at the University of Warmia and Mazury in Olsztyn in Poland in the presence of representatives of the Polish Ministry of Science and Higher Education and local governments, and representatives of the Polish astronomical and space sciences communities.

The new LOFAR stations will be located in Łazy (in southern Poland, operated by the Jagiellonian University in Krakow), Bałdy (in northern Poland, operated by the University of Warmia and Mazury in Olsztyn), and Borówiec (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.

The new map of the ILT showing the POLFAR stations (source: ASTRON)

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. And in particular, the Polish stations give ‘baselines’ of up to 1550 km in the array, making the ILT a much more capable instrument for high resolution imaging of detailed structues. The positions of the new stations also literally provide new angles on ionospheric tomography.

All components for the LOFAR stations, such as the manufacturing of thousands of antenna elements and electronics, are to be contracted out to industry. The construction of the three new stations will start immediately and is estimated to be completed before the end of 2015. 


Yesterday morning we were meant to do incoherent scatter radar (ISR) observations of the EISCAT VHF. This was in conjunction with a demonstration/prototype system that is also being tested at the KAIRA site (more on this in a forthcoming article!). Then, in the afternoon, we'd revert to solar observing.

However, due to various issues we ended up postponing the VHF ISR observations to the afternoon. Sure enough during that time there was two X-class solar flares. Yep, not one, but two. After months of radio silence what there the chances (pretty good, it seems!).

In any case we were observing nonetheless and there was a chance we might have seen something in the sidelobes of the tile beams. Sure enough there were several hints of natural emission, which may be from the sun.

Tuesday 10 June 2014

Aerial #L21 replaced

At 21:20 EEST, we replaced LBA aerial #L21.

Pikku Malla

Just a nice photograph today. This one was taken by Joona Keskitalo, looking across the shoreline and the frozen surface of Kilpisjärvi. The mountain in the background is Pikku Malla.

Pikku Malla (Photo: J. Keskitalo)

Monday 9 June 2014

RFI forest

On Friday evening we had an unusual few hours of RFI. The emission was broad band and came as distinct spikes. Normally the RFI situation at KAIRA is pretty good, so this sort of thing came as a bit of a surprise.

Zooming in on the above forest, one can see that the spikes are not regularly spaced and are occurring every 1-2 minutes or so. The spikes are one-sample or less in duration (that is, less than 1 second, which is the sample period we use for these sorts of statistics files).

Looking at a plot to show different frequency information indicates that this is broad band. The following is a median-filtered plot. The noise in the 10-20 MHz range is shotwave radio.

Sunday 8 June 2014

Using the snowmobile... in June!

This week just gone, we've been extending the reindeer fence... vertically. Due to the depth of the snow in this last season it has been possible for reindeer (and elk!) to get into the KAIRA compound. Therefore, we've gone around the entire perimeter and have added some additional height to all the fence posts. We'll be stringing out some additional wire later.

In order to get this work done, we've brought a snowmobile to the site. Why? Because there was at least a little bit of snow left and any excuse will do to use the observatory snowmobile.

The snowmobile arrives (Photo: D. McKay-Bukowski)

Loading up the snowmobile and trailer. (Photo: D. McKay-Bukowski)

Patrolling the perimeter fence. (Photo: D. McKay-Bukowski)

Friday 6 June 2014

More storm damage revealed

As the snow recedes we are find more and more horrors from the great blizzard of 2014. In addition to destroyed fencing etc., there appears to be a lot of array damage that was hitherto hidden. Perhaps the most surprising was finding a broken staafje (a small white fibreglass rod that joins the S-haakje to the HBA tile cover. The fact that this broke is pretty amazing as they are very strong.

Collapsed cell in Tile H65. (Photo: D. McKay-Bukowski)

Broken staafje(!) and S-haakje. (Photo: D. McKay-Bukowski)

Shattered frame on the LBA cable mausoleum. (Photo: D. McKay-Bukowski)

Collapsed LBA aerial #L05. (Photo: D. McKay-Bukowski)

Destroyed LBA aerial #L34. (Photo: D. McKay-Bukowski)

Thursday 5 June 2014

Swimming? Anyone?

Time for a nice photograph. This week we've had Joona Keskitalo on site, which means some good photography is beound to ensue. Joona posted this photograph on Twitter a couple of days ago, but it is so good, we're featuring it today. The shot is taken from the jetty at the shoreline near the Biological Station operated by the University of Helsinki. This is where we stay when working at the KAIRA site. This time last year, the ice had started to break (and yes, we were swimming), but its a bit colder this year... didn't stop some of us from swimming though! (Click on the image to enlarge it.)

The icy surface of Kilpisjärvi (Photo: J. Keskitalo)

Wednesday 4 June 2014

Snow situation at KAIRA

Hey! We're back on site again. Normally a very joyful occasion (this is, after all, the coolest LOFAR site on the planet), however this time it was marred by the fact that the receding snow is showing up more and more damage from the great blizzard of 2014.

Still, there is a quite a lot of snow to been seen, as these photographs show (taken on the evening of 02-Jun-2014).

Snow banks along the storage containers. These are
over 1,5m tall in places. (Photo: D. McKay-Bukowski)

Looking out over the lower field. Rivulets of water
are everywhere now. (Photo: D. McKay-Bukowski)

The gully behind the barracks. (Photo: D. McKay-Bukowski)

Fortunately, with this quantity of snow, there are no mosquitoes... yet.

Tuesday 3 June 2014

Visitors from Ettus Research and National Instruments at SGO

Yesterday we had Matt Ettus from Ettus Research and Leif Johansson from National Instruments visiting SGO. We had a one-day meeting on mainly EISCAT_3D and KAIRA related things. Naturally, the scope was in the software radio defined technologies and on how to use them with phased-array systems. Hence, today we feature two photos of the meeting.

Derek McKay (on the right hand-side) presenting KAIRA
to Markku Lehtinen (on the left hand-side), Leif Johansson
and Matt Ettus.

Markku Lehtinen and Matt Ettus in front of the 32-metre
EISCAT VHF receiver dish in Sodankylä.

Monday 2 June 2014

SGO history 1944: Lapland War and destroyed Observatory

I was browsing photos of the Finnish Wartime Photograph Archive, a project of the Finnish Defence Forces, and found a set of photos of the Observatory taken by an army photographer 30 October 1944. The photo title given at the site states: “Saksalaiset ovat perääntyessään tuhonneet maailman vanhimman observatorion Sodankylässä täydellisesti.”, i.e “During the withdrawal, the German troops have completely destroyed world’s oldest observatory in Sodankylä”. This was no surprise, as the German troops used the scorched Earth policy during the withdrawal, for example they practically burned all the buildings in Rovaniemi. Hence, Observatory was no exception in this unfortunate war.

It is interesting to read the Observatory annual report of 1944. This document was written by the Observatory Director E. Sucksdorff. According to the report, all the population of Lapland was evacuated during September 1944. The Observatory staff emptied their desks on the 15 September. They took all the recorded data with them, unprinted manuscripts, unfinished studies as well as most important observation and recording devices. The staff and all the material were relocated to Helsinki. However, it was impossible to take everything at short notice and much of the equipment was left behind. Observatory staff wrote notes in Finnish and German, which explained the special purpose of the site and asked that the facility would be left intact. The notes were placed in visible locations, such as on doors etc.

Unfortunately the notes did not help at all and, in practice, the entire Observatory was destroyed. Only an old, and rotten, pilot ball tower (pilotpallotorni in Finnish - for weather balloon experiments, I suppose) and some meteorological observation devices survived. Only ruins were found when Finnish Defence Forces arrived at the Observatory. Among the army personnel, was a photographer, who took some photos of the destruction. Today these photos are publicly available at This is a pretty unique site to explore the WWII happenings in Finland -- and well worth to visit. Hence, today we feature some photos of the burned Observatory site during the Lapland war year 1944.

The tower and meteorological observation devices were the
only untouched instruments at the site. Source: SA-kuva

Source: SA-kuva

Source: SA-kuva

Source: SA-kuva

Source: SA-kuva

Source: SA-kuva

Source: SA-kuva

Source: SA-kuva

Source: SA-kuva