Current snow depths

Currently (30-Nov-2013) the snow situation at KAIRA is as follows:

LBA -- Uniform snow coverage. Sample depth (L26) = 45 cm.

HBA -- Uniform snow coverage over tops of tiles. Slightly less on tiles on the northwest edge. Sample depth (H27) = 20 cm.

HBA snow corridors -- highly variable snow depths, ranging from 40 cm (near H59) to 165 cm (near H36).

General site -- again variable, depending on terrain, but roughly 50 cm.

KAIRA site conditions 2013.11.25

It is Friday again! But today, instead of a nice photograph, we have a short video for you. Earlier this week there was a pretty heavy snow fall at Kilpisjärvi. Our snow corridors are now about half full and with the wind picking up, there was quite a lot of drift snow banks about. Around midday, we took some video footage of various places around the site and have compiled them into a short video for you to see what KAIRA looks like at this time of year.

Direct link: http://www.youtube.com/watch?v=ut48VSVoFCk


Have a nice weekend!

Mountain crossing

Yesterday we drove up to EISCAT for a meeting on phase coding, and to take one of the crew up to EISCAT for the remaining experiment. We drove up during the day in pretty poor conditions and returned in the mid-afternoon. Of course, that means pitch darkness at this time of year.

The mountain pass, which had been a bit wet earlier was by now pretty treacherous and there were no fewer than three stuck lorries that needed to be passed along the way. In the example shown, the lorry managed to get part way up the incline, lost traction and then slid back down until it jack-knifed against the snow bank.

Jack-knifed lorry on the E8 between Skibotn and Kilpisjärvi.

A recovery vehicle came over from Finland to rescue it. However, having proceeded further it then came to a stop again, due to the fact that some of the recovery gear had been left behind. As we had the only car on the road, we returned to assist. In remote locations and difficult situations, everyone pitches in to help out.

So, yes, it was a slow and eventful trip back to Kilpisjärvi.

Sodankylän geofysiikan observatorio 100v.

Harking back to our celebrations of the 100-years of Sodankylä Geophysical Observatory, science journalist Jari Mäkinen presents a short video on Tiedetuubi. The text is in Finnish, but there is a lot to see of the host Observatory at Sodankylä. To quote from the Tiedetuubi website...

Sodankylän geofysiikan observatorio vietti syyskuun lopussa 100-vuotisjuhliaan ja Tiedetuubi kävi paikalla paitsi juhlimassa, niin myös tutkimassa mitä Sodankylässä oikein tehdään ja mitä sadan vuoden aikana on tapahtunut.

Visit their website here:   http://tiedetuubi.fi/?q=node/572

Enter the darkness

Today we just have a poignant photograph. The reason is that polar night is starting and we will not see the sun again for a while. Although we like the dark (dark for dark business, as they say), it is also a solemn moment.

On a grey and lonely day... (Photo: D. McKay-Bukowski)

Finnish EISCAT campaign week

This week, we will run a number of Finnish EISCAT experiments both in mainland and Svalbard. KAIRA will support most of the experiments. Monday-Tuesday Antti Kero will run ionospheric heating campaign titled heatncool. Wednesday-Thursday Lassi Roininen et al. have the TomoScand verification campaign. Alexander Kozlovsky will do measurements up in the islands in Longyearbyen. Anita Aikio et al. will make remote runs from Oulu.

Just to give you a clue of some experiments:

Heatncool - 25 and 26 Nov

To measure the D-region heating and cooling rates in a sub-millisecond resolution by superposing a sufficient number of short heater on/off modulations together. Raw data sampling makes the superposition possible.

TomoScand - 27 and 28 Nov

The objective is to verify the TomoScand ionospheric tomography reconstructions against the EISCAT measurements. 27 Nov mourning, we will point EISCAT mainland VHF to zenith with simultaneous KAIRA measurements allowing bistatic incoherent scatter radar measurements. With UHF we follow the trajectories of flybys of a COSMOS satellite. In order to guarantee transmitter stability, we will use regular EISCAT experiments (beata, bella etc).

28 Nov the measurement setup is similar to 27 Nov, except that we will do a daytime experiment. In addition, ESR Svalbard incoherent scatter radar will point at Az 180 El 78 (nearly field-aligned). This pointing direction is towards the Pan-Nordic TomoScand chains, thus allows good additional information for verification studies!

In addition to EISCAT and KAIRA, we will use Tromsø and Sodankylä ionosondes and GPS measurements (gps data handled by our visiting scientist Melessew Nigussie from Bahir Dar University, Ethiopia).

EISCAT heating control!

Snowmen

This has got to be the coolest snowman I've seen so far this year...

Researchers from SGO (Photo: A. Kero)

Frozen Kitinen

This week we have a guest photo, kindly provided by our recent KAIRA observer:

It's Photo Friday! 

The frozen river at SGO. (Photo: P. Martin)

Enjoy your weekend.   :)

Text & image credit: P. Martin

Stars over the HBA array

Another pretty picture for you. A long exposure of the night sky above the HBA, taken on one of the few clear nights that we have had recently.

Stars over the KAIRA HBA (Photo: P. Martin)

Text & image credit: P. Martin

Joint KAIRA/EISCAT observations

Continuing on with an overview of Poppy’s observations.



When not working on pulsar observations, Poppy has been running a riometry experiment that is also run at the LOFAR station in Chilbolton (UK).

The most exciting part of this involved simultaneous observations of the ionosphere with KAIRA, EISCAT at Tromsø, and Chilbolton. As KAIRA and EISCAT are co-located, they can be used to observe the same section of the ionosphere. This is done by observing zenith at both sites (using the VHF at EISCAT and using the LBA at KAIRA), then by pointing the UHF over KAIRA, and by pointing some of KAIRA’s beamlets over EISCAT. This allows us to simultaneously observe the ionosphere above both EISCAT and KAIRA using two different instruments, verifying KAIRA’s riometry observations.

A diagram of the simultaneous observations of the ionosphere
using EISCAT and KAIRA. (Credit:  P. Martin)

Derek sciencing [ed: this was Poppy's caption, not mine!] (Photo: P. Martin)

 

Text/images: P. Martin

Pulsars north of the wall

After enduring many weeks north of the wall, the visiting observer at KAIRA has finally returned home to sunny Southampton. Over the next couple of posts, we will give a brief overview of her observations using KAIRA.

Poppy Martin, a PhD student at the University of Southampton, has spent the past 5 and a half weeks based at KAIRA running an observing campaign. Whilst here, her primary aim has been to develop a pioneering new method of observing the ionosphere - by using pulsar observations to look at the Faraday rotation that occurs in the ionosphere.

Pulsars are rapidly rotating, highly magnetised neutron stars that emit a beam of electromagnetic radiation that sweeps through the sky like a lighthouse, causing us to observe a pulse whenever it is pointed at the Earth. They were first discovered in 1967 by Jocelyn Bell and Antony Hewish, and because the pulses occurred so regularly, there was an early hypothesis that they were actually aliens trying to communicate with us. In fact, the first pulsar was actually nicknamed LGM-1 (Little Green Men-1). 


Pulsars have been observed using KAIRA before (see http://kaira.sgo.fi/2012/09/first-pulsar-observation-at-kaira.html). However we have developed this method, and can now observe up to eight pulsars simultaneously.

An example of a pulsar observation made using the HBA.
 (Image: P. Martin)

Text/image credit: P. Martin

Inverse Days 2013 press release

(Suomenkielinen lehdistötiedote alla)

KAIRA/SGO team will organise the 19th Inverse Days in Inari Dec 11-13. Inverse Days is the annual meeting of the Finnish Inverse Problems Society. It is known for the high scientific level of the meeting as well as the walrus wrestling, the official sports event of the society (which will take place in the evening programme).

--------------------------------------------

Press release, University of Oulu, Sodankylä Geophysical Observatory

Mathematics of Planet Earth - A High-level Inverse Problems Conference in Inari

Finnish Inverse Problems Society, in collaboration with Sodankylä Geophysical Observatory, have organised the 19th Inverse Days conference at the Sámi cultural centre "Sajos" in Inari. It will be preceded on the 10 December by a thematic day on geospace and atmospheric research, to be held in Sodankylä Geophysical Observatory. Altogether around 100 researchers from Finnish and foreign universities and research organisations are expected to participate the events.

Inverse problems is a domain of applied mathematics. Typical examples of inverse problems include atmospheric and near-space radar measurements and clinical imaging in hospitals. Inverse Days 2013 belongs to the UNESCO project "Mathematics of Planet Earth" and the conference is organised around the different themes of this project. Mathematical and computational methods for inverse problems will be represented during the conference for example in climate change, seismology, atmospheric research and forest monitoring.

The origin of the Finnish Inverse Problems research is in incoherent scatter radar data analysis and modelling carried out by Sodankylä Geophysical Observatory in the 1980s. Nowadays inverse problems research is carried out in a number of universities in Oulu, Helsinki, Lappeenranta, Kuopio, Tampere and Jyväskylä. The inverse problems groups of these universities comprise the Centre of Excellence in Inverse Problems Research funded by Academy of Finland (2012-2017). The most recent achievement of the Sodankylä group is the building of the Kilpisjärvi Atmospheric Imaging Receiver Array (kaira.sgo.fi), which is the largest radio telescope on Finnish territory. This instrument is used for atmospheric, near-space, solar system and deep space studies.

By bringing the Inverse Days to Inari, and more specifically to Sajos, the Finnish Inverse Problems Society wants to emphasise the growing importance of Arctic regions and to respect the status of Sámi people in the region, Europe's only indigenous people. 

More information:
University of Oulu, Sodankylä Geophysical Observatory
Research Professor Markku Lehtinen, markku.lehtinen@sgo.fi, +358 400 399 982
Researcher Lassi Roininen, lassi.roininen@sgo.fi, +358 40 482 7773

University of Helsinki, Department of Mathematics and Statistics
President of the Finnish Inverse Problems Society, Professor Samuli Siltanen, samuli.siltanen@helsinki.fi +358 40 594 3560


Inverse Days: inverse-problems.org/id2013
Mathematics of Planet Earth: mpe2013.org








--------------------------------------------


Lehdistötiedote, Oulun yliopisto, Sodankylän geofysiikan observatorio


Maan matematiikkaa - Inversio-ongelmien huippukokous Inarissa

Suomen inversioseura ja Sodankylän geofysiikan observatorio järjestävät Inarin saamelaiskulttuurikeskus Sajoksessa 19. Inversiopäivät 11.-13.12.2013.  Tiistaina 10.12. Sodankylän geofysiikan observatoriossa järjestetään lähiavaruuden- ja atmosfääritutkimuksen teemapäivä. Tapahtumiin odotetaan noin sataa osallistujaa kotimaisista ja ulkomaisista yliopistoista ja tutkimusorganisaatioista.

Inversio- eli käänteisongelmat on sovellutun matematiikan osa-alue, jonka käytännön esimerkkejä ovat ilmakehän ja lähiavaruuden tutkamittaukset ja lääketieteellinen kuvantaminen. Tämän vuoden inversiopäivät järjestetään UNESCOn sateenvarjoprojektin “Mathematics of Planet Earth” -merkeissä. Inversiopäivillä esitellään matemaattisia ja laskennallisia menetelmiä esimerkiksi ilmastotutkimukseen, seismologiaan, lähiavaruuden ja metsien tutkimukseen.

Suomen inversio-ongelmien tutkimus juontaa juurensa Sodankylän geofysiikan observatoriossa tehtyyn lähiavaruuden sirontatutkamittausten mallintamiseen. Nykyään inversiotutkimusta harjoitetaan Oulun yliopiston lisäksi Helsingissä, Lappeenrannassa, Kuopiossa, Tampereella ja Jyväskylässä. Kyseisten kaupunkien inversioryhmät muodostavatkin Suomen Akatemian inversiotutkimuksen huippuyksikön. Sodankylän ryhmän viimeisin saavutus on Kilpisjärvelle rakennettu Suomen suurin radioteleskooppi, jota käytetään niin ilmakehän kuin syvän avaruudenkin tutkimukseen.

Inversiopäivien tuonnilla Inariin ja Sajokseen Suomen inversioseura haluaa korostaa erityisesti arktisten alueiden kasvavaa merkitystä ja kunnioittaa Euroopan ainoan alkuperäiskansan saamelaisten asemaa alueella. 

Lisätietoa:
Oulun yliopisto, Sodankylän geofysiikan observatorio
Tutkimusprofessori Markku Lehtinen, markku.lehtinen@sgo.fi, +358 400 399 982
Tutkija Lassi Roininen, lassi.roininen@sgo.fi, +358 40 482 7773

Helsingin yliopisto, Matematiikan ja tilastotieteen laitos
Inversioseuran presidentti, professori Samuli Siltanen, samuli.siltanen@helsinki.fi +358 40 594 3560
Inversiopäivät: inverse-problems.org/id2013
Mathematics of Planet Earth: mpe2013.org

Extreme weather at KAIRA

Yesterday, we had some pretty extreme weather at KAIRA. Overnight there had been a lot of snow and, as the skies cleared in the morning, some extremely high winds picked up and lashed the site.We were out first thing to collect some data disks and getting onto the site, and then into the RF-container, was quite a challenge.

Sheltering by the RF-container, I managed to take this photograph. Standing there, you could see great clouds of snow being swept up the northwest slope and hurled over the HBA tiles. The image doesn't really capture the ferocity of the morning, but perhaps it gives a hint of the conditions we had.

Clouds of snow blasting over the KAIRA HBA array (Photo: D. McKay-Bukowski)

As far as we can tell, the telescope has survived with no damage. However, a full inspection will not be carried out until later today. Yesterday, we also managed to travel on to Tromsø (to take the observer to the airport) and cross the mountain passes safely both there and back. Thankfully we had the heavy four-wheel drive and not one of the lighter observatory vehicles.

Extreme weather warning

According to the Norwegian and Finnish Weather services, we are expecting extreme weather in the west and north west of Fenno Scandinavia today. In fact it already started last night with a dramatic increase in the wind.

The weather map over Trondheim and Bodø... not looking good! (source: yr.no)

KAIRA was checked at 20:00 local time last night and also again this morning. The report has yet to be posted. Additionally, we will attempt to cross the mountain passes into Norway in order to get our visiting observer to Tromsø airport for an outbound flight. Whether the passes remain open and whether the flights remain operational remains to be seen.

Current status: high winds and heavy snow.


Links:

• http://www.yr.no/sted/Finland/Lappland/Kilpisj%C3%A4rvi/ (Norwegian)
• http://ilmatieteenlaitos.fi/saa/enonteki%C3%B6/kilpisj%C3%A4rvi (Finnish)

Sun and cloud

Just a nice photograph for Friday.

Sunshine setting the clouds afire. (Photo: D. McKay-Bukowski)

Have a nice weekend!

The reindeer fence

The reindeer fence is holding up well. Not only have we kept the reindeer out of the antenna fields, but it is also surviving well against the snow. The fence is of timber posts with open wire mesh. Because the antennas are up on a mound, the fence is below the ground plane in most places and therefore does not interfere with the radio signal.

Looking along the reindeer fence towards Norway. The HBA array
is on the mound up on the right. (Photo: D. McKay-Bukowski)

Alongside the lower part of the compound, there is the main snowmobile trail that runs from Finland to Norway. It runs just next to the fence and can be seen in places marked with a red diagonal cross.

The corner of the compound. Saana is in the background and the trail
leads off down past the customs station. (Photo: D. McKay-Bukowski)

We've now put up additional reflective markers  along this fence to ensure it is visible in the dark. We wouldn't want a snowmobile to accidentally run into it!

Subband to frequency checking

On Monday, we reported on the checking of the cells within the HBA tiles. As part of the same test, we also checked on the frequencies. Although there had been some discussion regarding the registration between the subband and the frequency due to some confusion related to the documentation, we had this pretty well resolved a while ago. However, there is nothing like actually checking it for real. Therefore, as part of the general testing day, for the cells, polarisations and other things, we checked of the frequencies as well.

To do this, we built a test aerial. This was a crude dipole made with some wire, a broom and a snow-post. The coax lead from the dipole went back into the site office, where we had a calibrated signal generator.

Our hi-tech aerial! (Photo: D. McKay-Bukowski)

Using this, we could inject signals and look at the corresponding response. Here is one example output, using RCU mode 5:

The colour indicates signal strength. Red is strong, yellow is medium and blue is weak. Of course, most of the spectrum is weak. The injected signals, in time order, were 149.902, 150.000 and 150.097 MHz. Each sample is 10 seconds in duration. We ran each for a about 30 or so seconds, with a similar gap in between.

As you can see, there was the best response at exactly 150.000 MHz, with no spill into adjacent channels. Additionally, the signals injected on the subband boundaries do tend to appear roughly equally in both channels.

Like our other tests, this came as no surprise. However, it is always useful to double check all aspects of the measurements and verify the data integrity.

Shifting snow

As mentioned in yesterday's post, we carried out a number of tests on the HBA. Some of these required actually getting into the tile itself (for example, to carry out the polarisation checks). And of course, doing the dipole and RF-clock tests is always easier when the tile is clear from snow. So, although the small amount of snow does not significantly affect our radio measurements, we had to clear it off anyway.

Today's photograph is a shot of just that... yours truly shifting snow off HBA #H25.

Shifting snow. (Photo: P. Martin)

Cell registration

Data Monday...

There has been some discussion recently regarding not just polarisation for the HBA, but also cell registration too. As we were already conducting some other tests, we decided to check on this too. In other words, checking the registration of the individual antenna cells within the tile itself.

The cells within the tile are numbered 1-16, starting in the top left and working across. The position offsets of these are set using the iHBADeltas.conf file.

Although we have been reliably using the system, it has not actually been tested directly. To do this, we created a temporary dipole (some wire, a broom and a snow post) and also a screen (kitchen foil between cardboard, taped to an HBA lids' pallet). Using these, we could both transmit into and block signals for a given cell in the tile.

We also made use of some special rspctl commands to disable all the tile elements, except one. This allowed us to check each cell individually.

The only problem in this was getting the snow off the tile.

A home-made RF block. (Photo: D. McKay-Bukowski)

Of course the test was completely successful, but it is always very gratifying to get such confirmation. The configuration is as follows:

1	2	3	4
5	6	7	8
9	10	11	12
13	14	15	16

Cell #1 is located at the western-most corner of the tile. The cables for the tiles exit underneath cells #14 and #15. Note that this is the not the usual layout for HBA tiles in a LOFAR station. It is just that KAIRA has a slightly different orientation in order to accommodate EISCAT experiments.

Fiery skies

Today's photograph is from a little while ago now. It was perhaps the last day before the snow started, and there was a particularly spectacular sunrise. In amongst the clouds is the faint silhouette of Saana.

A fiery sunrise over the KAIRA LBA (Photo: D. McKay-Bukowski)

Snow on the branches

Just another nice image. Today's photograph shows some of the snow on the branches of the birch trees near the KAIRA site.

Snowy branches near KAIRA (Photo: D. McKay-Bukowski)

There is not much sun left now for this year. And, what little daylight there might be, it is often cloudy, which is typical at this time of year. So, we're making the most of the last of the sunny photographs that we have!  :-)

The route from EISCAT-Norway to KAIRA

The road from the EISCAT site at Ramfjordmoen near Tromsø back to KAIRA is quite scenic. As it is Friday (our regular day for nice photographs), we've decided to post a few from the recent Southampton/ campaign that KAIRA supported.

Looking up the valley from EISCAT. (Photo: D. McKay-Bukowski)

Near Lyngenfjord (Photo: D. McKay-Bukowski)

Near Langmoen (Photo: D. McKay-Bukowski)

Have a nice weekend everyone!

EISCAT VHF

Yesterday we showed some photographs of the EISCAT 32m UHF system. Today, we are featuring the 120x40m VHF system. This antenna is actually split into four "panels", which are 30x40m each and can be controlled in elevation independently.

The EISCAT VHF system with the nearest panel tipped
forward. Note the person on the access-way
for scale. (Photo: D. McKay-Bukowski)

The EISCAT VHF system with all panels aligned.
The feed is off-axis, so in this configuration the radar
beam is actually straight up. (Photo: D. McKay-Bukowski)

Looking along the feeder-bridge. The crossed-
dipoles are used for both transmission and
reception. (Photo: D. McKay-Bukowski)

The observing project was being run by the University of Southampton, UK, which has time on both the EISCAT UHF and VHF systems as well as KAIRA.

EISCAT UHF

A couple of weeks ago, the KAIRA team was at the EISCAT radar site at Ramfjordmoen, near Tromsø, to carry out some observations. We planned to control KAIRA remotely and do the observations with EISCAT locally. It didn't quite work out that way, as an unexpected power failure required a "quick" return to the site for a reset, but otherwise all went okay.

The weather we had in Tromsø was lovely and we took some photographs to share. Today we are featuring the 32m UHF radar.

EISCAT transmitter hall, control building and UHF 32m dish. (Photo: D. McKay-Bukowski)

The 32m UHF dish, seen from the feeder-bridge of the VHF antenna. (Photo: D. McKay-Bukowski)

Floating at the top of the world

Today we have a nice photograph of the midday sun over the KAIRA site. There is not much sun left now, with Polar Night about to start. So we're going to make the most of it!

Sun and clouds over the KAIRA site. (Photo: D. McKay-Bukowski)

The clouds make it seem like the entire observatory is floating at 10 000 m above sea level!

KAIRA LBA polarisation orientation

Last week, we showed the polarisation orientation of the High-Band Antenna (HBA) elements of the KAIRA array. And this week, it is the turn of the Low-Band Antenna (LBA) array.

SyncOptic unit installed

A while ago we took delivery of a SyncOptic repeater unit from ASTRON. A couple of weeks ago this was installed at KAIRA as part of the winter maintenance and upgrade expedition. And today, we have a photograph of the installed unit.

The new clock system at KAIRA (Photo: D. McKay-Bukowski)

In the photograph, the small box on the shelf on the left is the GPS receiver. The larger box next to it with the matrix of BNC connectors is the rubidium atomic clock. The new SyncOptic unit is underneath (the unit marked LOFAR/ASTRON).

Border mountains

Today's photograph shows the mountains along the border between Finland and Norway. The shot was taken from atop the RF-container, looking out across the lower field.

Looking west-northwest towards Norway. (Photo: D. McKay-Bukowski)

Sky above, snow beneath

Today we have another photograph of the snow conditions at the KAIRA site:

HBA, RF-container, site office and one of the storage containers.
Oh, and plenty of fresh snow too. (Photo: D. McKay-Bukowski)