Surveying the field

The top priority task is to conduct an initial survey of the proposed deployment area. This was carried out today at the site using a simple theodolite, tape and survey stick... backed up with a GPS receiver! During the survey, a number of set positions were used. This photograph shows the theodolite set up at the primary position.

During the surveying work a number of reindeer passed by to see what we were doing!

Looking across the theodolite, there is a nice view of the area where the low-frequency array could possibly be deployed. One of the survey team can be seen holding the 5-metre survey stick.

Test site at Kilpisjärvi

Although we are confident that the antennas will resist the harsh Arctic conditions, it is necessary to conduct some 'winter tests' with real hardware, in order to prove our assessment. Therefore, on the proposed site, we will deploy two 'test tiles'. These will be left over the winter and occasional checks will be made to evaluate their condition.

However, before the tiles can be deployed, it is necessary to survey the proposed area. Here are a few photographs of the site. In the first, the rocky area in the foreground is where the array is likely to be deployed.


In the next image, there is another view across the site. And, of course, there is another glimpse of some of the spectacular surrounding scenery.

Two types of antennas

The KAIRA project will make use of proven LOFAR antenna designs. LOFAR is the Low Frequency Array — a pan-European radio telescope project that is currently under construction.

There are two main types of LOFAR antennas. These are the so-called 'low-band' and 'high-band' antennas. The low-band antennas are aerials, covering the range 30 to 80 MHz. Each one stands approximately 1.8m tall, and has a 3 × 3-metre base. The high-band antennas are tiles and are designed to operate in the range 120 to 240 MHz. These tiles are only 0.5 metres tall, but have a larger 5 × 5-metre footprint.

Kilpisjärvi Atmospheric Imaging Receiver Array

Welcome to KAIRA! This is the weblog of the Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA). This is a project of the Sodankylä Geophysical Observatory, principally funded by the University of Oulu in Finland. KAIRA is a dual array of omni-directional VHF radio antennas. It makes extensive use of the proven LOFAR antenna and digital signal-processing hardware, and can act as either a stand-alone passive receiver, as a radar receiver for the VHF transmitter in Tromsø, or for use in conjunction with other Fenno-Scandinavian VHF experiments. It will be used for engineering experiments as well as conducting scientific observations of atmospheric and astrophysical phenomena. In additional to being a powerful observing instrument in its own right, KAIRA will act as a pathfinder for technologies to be used in the proposed EISCAT-3D system.