An announcement of the project (suomeksi / in Finnish language) has been posted on the University of Oulu web site.
Friday, 28 January 2011
SGO rakentaa Kilpisjärvelle radiovastaanotinaseman
An announcement of the project (suomeksi / in Finnish language) has been posted on the University of Oulu web site.
Daily Image
Today, KAIRA receives the honour of being featured as the ASTRON Daily Image!
Every day, ASTRON (the Netherlands Institute for Radio Astronomy) posts an interesting image from the world of radio astronomy. These images vary between famous astronomers, the latest observational results and developments in new instruments and telescopes.
Today it is our turn to be featured, with a report on the deployment of the two test tiles which was carried out last October, and how they have fared so far in the winter conditions.
Every day, ASTRON (the Netherlands Institute for Radio Astronomy) posts an interesting image from the world of radio astronomy. These images vary between famous astronomers, the latest observational results and developments in new instruments and telescopes.
Today it is our turn to be featured, with a report on the deployment of the two test tiles which was carried out last October, and how they have fared so far in the winter conditions.
Friday, 7 January 2011
Mid-winter conditions
Taken in the middle of the day in early January, here are our test tiles in action. In the first picture we look past the snow-depth marker in the direction of the raised tile. Although there is 100 to 150 millimetres of snow on it, the situation remains reasonable.
The ground tile, on the other hand, is completely covered... as we expected. Drifting snow banks up against the side of the tile and covers it in a thick, uneven layer.
We shall continue to monitor the progress of the tiles as the Arctic winter drags on.
The ground tile, on the other hand, is completely covered... as we expected. Drifting snow banks up against the side of the tile and covers it in a thick, uneven layer.
We shall continue to monitor the progress of the tiles as the Arctic winter drags on.
Wednesday, 5 January 2011
The sky is the limit?
The main purpose of the new Kilpisjärvi atmospheric receiver array is to function as a remote station for the VHF incoherent scatter radar of the EISCAT Scientific Association located in Tromsø, Norway. Because the receiver will be constructed using LOFAR hardware, it will have a usable frequency band covering 30-240 MHz, with only a small gap where FM broadcast stations are located (80-120 MHz). Due to the large number of antenna elements, the standard antenna array can receive along 254 narrow beams. KAIRA can be used in a number of different ways:
- Wide band imaging riometer, as a complementary instrument to the IRIS riometer located close by. As a riometer, KAIRA can be used without any radar transmitter to study mesospheric (D region) ion chemistry and the effects of active ionospheric modification experiments (Heating) carried out at EISCAT Tromsø.
- In terms of meteor studies, there are a number of possible transmitters in the vicinity that will allow measurements of specular meteor trails, allowing for accurate orbital element determination. In addition to this, there are several meteor radars close by that might yield usable echos.
- It remains to be seen if actual mesosphere-stratosphere-troposphere (MST) measurements can be done, as the site is located fairly far from the nearest MST radar transmitters. At least mesospheric measurements should be feasible.
- Passive radar using digital radio broadcasts.
In addition to these there are several other possible uses for KAIRA as shown in the figure on the right column of this blog.
There are also several smaller instruments that could be co-located with KAIRA to make the site a truly versatile platform for atmospheric studies. Such installations will be considered together with our collaborators in due course.
Tuesday, 19 October 2010
Deploying the test tiles
Today the two test tiles were placed on the site. A snow-plough lorry with a loader crane was used to lift the tiles into position. For the tile that was put directly onto the ground, this was moderately straightforward. However, the raised frames made things somewhat more tricky.
Once the tiles were in place, the lids and covers could be applied. We'll no doubt explain this in more detail when we write about the actual placement of the final antennas. But for now, it will suffice to say that this means applying covers and securing the tiles to the ground.
As it turned out, we were just in time. As the second tile was placed and we started the covering and securing, the snow started to fall. Within 10 minutes, there was already a reasonable dusting of snow over the tiles, tools and equipment.
In the foreground of this image, the low tile can be seen while in the background the raised tile is still being secured.
With the work done, it was time to clear up. Safety markers were put up around the area and signs were erected to explain what on earth these strange things are!
The signs explain that these are antennas under test. They are written in four languages: Sami, Bokmål, Finnish and English.
Once the tiles were in place, the lids and covers could be applied. We'll no doubt explain this in more detail when we write about the actual placement of the final antennas. But for now, it will suffice to say that this means applying covers and securing the tiles to the ground.
As it turned out, we were just in time. As the second tile was placed and we started the covering and securing, the snow started to fall. Within 10 minutes, there was already a reasonable dusting of snow over the tiles, tools and equipment.
In the foreground of this image, the low tile can be seen while in the background the raised tile is still being secured.
With the work done, it was time to clear up. Safety markers were put up around the area and signs were erected to explain what on earth these strange things are!
The signs explain that these are antennas under test. They are written in four languages: Sami, Bokmål, Finnish and English.
Monday, 18 October 2010
Preparation work
The idea was to deploy the tiles before the first winter snows arrived. And although there was some scattered patches of snow on the ground when the team arrived, it certainly wasn't anything prohibitive.
The first step for placing the two test tiles was to level the patches of ground where the tiles would go. This was done with the help of a laser level (see here glaring into the camera lens).
Once the two areas were level, the frames could be assembled on the northern patch. As explained in an earlier post, we intend to put out two tiles. One will go on a raised platform made of open timbre frames, and the other will go directly to the ground (like in conventional LOFAR stations).
Once the frames were put in place, we took delivery of the tiles themselves. These arrived on an articulated lorry and were unloaded in the afternoon.
When packed, the tiles are stood vertically, folded over. At 5 metres long, and 2.5 metres high, they are actually quite vulnerable in this position. As a result, we quickly assembled a support frame that would secure them overnight, ready for tomorrow's deployment.
The first step for placing the two test tiles was to level the patches of ground where the tiles would go. This was done with the help of a laser level (see here glaring into the camera lens).
Once the two areas were level, the frames could be assembled on the northern patch. As explained in an earlier post, we intend to put out two tiles. One will go on a raised platform made of open timbre frames, and the other will go directly to the ground (like in conventional LOFAR stations).
Once the frames were put in place, we took delivery of the tiles themselves. These arrived on an articulated lorry and were unloaded in the afternoon.
When packed, the tiles are stood vertically, folded over. At 5 metres long, and 2.5 metres high, they are actually quite vulnerable in this position. As a result, we quickly assembled a support frame that would secure them overnight, ready for tomorrow's deployment.
Sunday, 17 October 2010
Frames to go!
In order to limit the amount of drift snow that banks up on or against the antennas, the KAIRA project plans to put the high-frequency tiles on a raised platform, made from a series of frames. By raising the tiles, they will be subjected to greater wind speeds and will avoid the immediate ground boundary layer.
To test this, and various other concepts, two test tiles will be deployed at the site this year. They will be monitored over the winter and fully inspected in the spring. Of the two tiles, one will be placed on a 1-metre high platform and the other directly to the ground (like is done at conventional LOFAR sites).
The deployment of these test tiles will be carried out over the next couple of days. And, although the tiles themselves will be delivered directly to the site, the frames will be taken up from the institute.
In this photograph, the set of timber frames has just been loaded onto the trailer, ready to be towed up to the site.
To test this, and various other concepts, two test tiles will be deployed at the site this year. They will be monitored over the winter and fully inspected in the spring. Of the two tiles, one will be placed on a 1-metre high platform and the other directly to the ground (like is done at conventional LOFAR sites).
The deployment of these test tiles will be carried out over the next couple of days. And, although the tiles themselves will be delivered directly to the site, the frames will be taken up from the institute.
In this photograph, the set of timber frames has just been loaded onto the trailer, ready to be towed up to the site.
Subscribe to:
Posts (Atom)