Wednesday, 16 April 2014

KAIRA -- lyhytdokumentti

Last week we published a film on KAIRA. Today, we have the film again, but with Finnish text/subtitles.



KAIRA on Kilpisjärvelle rakennettu ilmakehän, lähiavaruuden ja syvän avaruuden tutkimukseen tarkoitettu radioteleskooppi. Sen on rakentanut ja sitä operoi Oulun yliopiston Sodankylän geofysiikan observatorion. KAIRA-lyhenne tulee englanninkielisisestä projektinimestä Kilpisjärvi Atmospheric Imaging Receiver Array.

KAIRA-vastaanottimessa on kaksi antennikenttää, joista matalampitaajuinen niin sanottu LBA-kenttä mittaa taajuusalueella 10-90 MHz ja korkeampitaajuinen HBA-kenttä alueella 110-270 MHz. KAIRA voi toimia osana eurooppalaista sirontatutkajärjestelmää EISCATia. Norjan Tromssassa sijaitsee 224 MHz:n VHF-lähetin, jonka ionosfääristä sironnutta signaalia voidaan vastaanottaa Kilpisjärvellä. Lähitulevaisuudessa tulemme rakentamaan osana kansainvälistä yhteistyötä uuden hajautetun sirontatutkajärjestelmän Kalotin alueelle. Tämä projekti kulkee nimellä EISCAT_3D. Siinä tarvittavaa tekniikkaa kehitetään KAIRA-asemalla!

KAIRAn antennikentät on alunperin suunniteltu LOFAR-nimiseen radioastromiaprojektiin. Voimmekin käyttää radioastronomiaan suunniteltuja antenneja ja signaalinkäsittelyä hyvin suoraan ilmakehän ja lähiavaruuden tutkimukseen. Luonnollisesti teemme yhteistyötä useiden LOFAR-asemien kanssa eri radioastronomiaprojektien kanssa.







Tämä lyhytdokumentti kertoo KAIRAn rakentamisesta, asemalla tehtävästä tutkimuksesta ja EISCAT_3D-projektin pitkän tähtäimen näkymistä. KAIRA-aseman rakentamisen on rahoittanut Oulun yliopisto, Euroopan aluekehitysrahasto Lapin liiton kautta ja Sodankylän kunta.

Tuesday, 15 April 2014

FIN 1

I was in London the other week when I saw a car with a cool number plate... "FIN 1". The fact that it was parked outside the Finnish Embassy might not be a pure coincidence...


I wonder who gets "FIN 2"?

Monday, 14 April 2014

Video of ionospheric scintillation

Recently, we ran a small article on ionospheric scintillation and how dramatically it can change depending on atmospheric conditions. A few days later we showed two more interesting plots, both to the same scale, which demonstrated how substantial the different ionospheric scintillation conditions can be.

However, there is nothing quite like a video to really show how the scintillation can affect the signal. So today, we have just that!

What we did was make all-sky images for each of the two extremes shown in that last post we made on the topic.






The observing frequency was the same in both cases 58.594 MHz), 1 second integration per frame, 195.3 kHz bandwidth. The sequence is sped up somewhat (5 minutes data in about 30 seconds of video). As the time of day was the same in both instances, so the radio sky is in roughly the same orientation.

On the 25.12.2013 (left), the ionosphere exhibited extreme scintillation. The two bright sources (Cas A and Cyg A) are flickering quite dramatically. However, exactly two days later (27.12.2013, right), the ionosphere was relatively stable and the brightnesses of the two strong radio sources remain steady.

Sunday, 13 April 2014

Impacts of space weather

Space weather is an important issue and many nations are now realising the implications of forecasting, assessing risk and monitoring for space weather events.

The Royal Academy of Engineering (RAEng) in the United Kingdom last year published a good overview of the British view entitled "Space weather: impacts on engineered systems, infrastructure and society".

http://www.raeng.org.uk/societygov/policy/current_issues/space_weather/


The University of Birmingham (UK) works closely with the RAEng and has announced a fully Funded PhD place available in the Space Environment and Radio Frequency (RF) Engineering Group. The UK placement project is as follows:

Comprehensive, global and timely specifications of the earth's ionosphere are required to ensure the effective operation, planning and management of many radio frequency systems. Many techniques have been developed to measure ionospheric refractivity; these include ground and space - based ionosondes and the use of Global Positioning System (GPS) measurements made with both ground and space - based receivers.
Ionospheric data assimilation systems are currently under development that will combine disparate ionospheric measurements with an ionospheric model. The problem is mathematically under - determined since the amount of information that can be extracted from most ionospheric measurements is low compared to the required resolution of the electron density field under investigation. Therefore it is necessary to utilise a priori information about the state of the ionosphere in order to solve the inverse problem. Many inverse techniques have been proposed; however, this project will investigate the application of the local ensemble transform Kalman filter (LETKF) to physical models of the ionosphere/thermosphere system. The LETKF is a method whereby the data assimila tion is performed in local “regions” around each model grid point. Each region is processed independently, naturally leading to parallelisation, and the grids are later assembled into the global analysis. The LETKF has been well - tested and shown to be both computationally efficient and flexible. However, it has not yet been applied to the ionosphere. The intention of this project is to achieve a significant improvement in current ionospheric forecasting.

The project will be conducted within the Space Environment and RF Engineering group at the University of Birmingham. However, it is anticipated that the work will involve collaboration with researchers in Europe and the USA.

One fully - funded studentship (tax - free stipend of £13863* per annum) is available for Home/EU students to begin this inter - disciplinary 3 - year programme in October 2014.
*subject to inflationary variation Applications are open to students that have, or expect to obtain, a 1st class degree (or equivalent EU/overseas degree) in a wide variety of scientific disciplines including mathematics, physics and natural sciences. Due to the nature of the project, the applicant must be able to demonstrate a high level of mathematical ability.
If you are interested in this UK-based PhD position at the University of Birmingham, then informal enquiries should be made to m.angling@bham.ac.uk .

Friday, 11 April 2014

Perfect April Afternoon

During last weeks, we have been enjoying perfect winter weather and sunny days in Sodankylä! Today we have a photo of the main building of the observatory and EISCAT antenna taken on the Kitinen river during one of sunny April afternoons.




Thursday, 10 April 2014

2014 LOFAR Science Workshop conference dinner

The conference dinner for the 2014 LOFAR Science Workshop was held in the Pakhuis de Zwijger on the waterfront in Amsterdam. With so many fantastic talks during the day, the entire evening was abuzz with amazing discussions and ideas. And, to keep everything focused further, the organisers had asked for speakers to provide high-resolution images of their projects and results. These were projected onto nine massive screens that surrounded the eating area.




Wednesday, 9 April 2014

KAIRA film

At the LOFAR Science Workshop 2014 in Amsterdam, we premièred the KAIRA film. This was produced by SiteEye in conjunction with Sodankylä Geophysical Observatory, U. Oulu, ASTRON, EISCAT, and many others. (Versions with subtitles in many languages will be posted later.)



Enjoy!