Monday, 1 September 2014

KAIRA spectral riometry paper out!

I'm happy to announce that our proof-of-concept study on the electron density profile estimation based on the KAIRA spectral riometry measurement has been finally published in the Geophysical Research Letters, please have a look:

Kero, A., J. Vierinen, D. McKay-Bukowski, C.-F. Enell, M. Sinor, L. Roininen, and Y. Ogawa (2014), Ionospheric electron density profiles inverted from a spectral riometer measurement, Geophys. Res. Lett., 41,  doi:10.1002/2014GL060986

By comparing our spectral riometry results to a simultaneous EISCAT VHF measurement, we were able to show that the methodology works, at least under conditions of relatively strong ionisation. This builds confidence towards continuous monitoring of height-dependent D-region ionisation by spectral riometry.

Friday, 29 August 2014

Typical KAIRA

Today's photo has a bit of everything. The LOFAR HBA tiles, the LBA array in the background, Saana dominating the horizon, the storage containers and site area, and our trusty observatory vehicle.

The KAIRA site (Photo: D. McKay-Bukowski)

Thursday, 28 August 2014

Valhalla

Always curious to try local produce, I tried this herb liqueur by Koskenkorva. It comes in a matt black bottle, rates at 35% and is ominously titled:  "Valhalla".



Herb ingredients are: Angelica achangelica, Artemisia absinthium, Achillea millefoium, and Glycyrrhiza glabra. 

Wednesday, 27 August 2014

Roadworks

Driving back late one night from KAIRA to SGO there was (yet another) hold up. This time roadworks. In fact there is a bridge under repair on the route from Kittila to Sodankylä and this is where we got stuck.


We were the only car.

And yet the delay was... well...

Plasma lines at Arecibo

25 MHz wide plasma line profile at Arecibo, 2.5 seconds of integration. 
A while ago, Thomas covered the Arecibo radar school (you can see our black rack receiver on the table in one his pictures). During the school, a little bit of data taking took place. Between his lectures, Phil Erickson ran data collection with our 25 MHz digital receiver, in anticipation for a longer campaign that will occur later this year. As I wasn't in Puerto Rico, and I've been traveling elsewhere, I'm only now starting to analyze the results. But they are quite nice.  The system can pretty much do what the existing 5 MHz wide Pentek system can do, but at 25 MHz bandwidth, allowing us to measure plasma line profiles such as this. You'll probably need to zoom in the picture to pick out the narrow plasma line. There is also a higher resolution version on line here.

Anyway, this is quite a successful first try. The IF will need to be at a different frequency than 260 (e.g., 264 would be nice), as plasma line below 10 MHz folds, and can also be seen "sliding" down from +12.5 MHz too. Another option is to bring a tuner to shift the band to a lower IF. Also, the wide band IF doesn't seem to be wide enough. The upshifted line isn't that visible due to filter roll-off. 

Monday, 25 August 2014

Data extraction

There are numerous computers in the RF-container, which handle data processing, control and storage. One of these has now been taken out and has been moved back to SGO for use there in some of our interferometric riometry development work. During the extraction of this data system, we had the side cover of the RF-container signal processing racks off, thus once can see the other computers, network gear, etc.

KAIRA data systems (Photo: D. McKay-Bukowski)

Sunday, 24 August 2014

Missing in action

Today's photograph shows the frameset of HBA tile #75. Or, we should say... the former HBA tile #75. It is missing due to a severe blizzard that swept through the site at the beginning of the year. We are still waiting for a quote from ASTRON to get this replaced.

Frameset for HBA tile #75 (D. McKay-Bukowski)