KAIRA is a new facility and so it is yet to realise its full potential. However, already it has accomplished several new innovations. Here we point out a few of the highlights
First all-sky interferometric riometry
Unlike multibeam riometers, which form discrete beams on the sky, the interferometric technique permits all-sky sampling of incoming cosmic radio noise emissions resulting in a spatially-continuous radiogram of the entire sky. The map of the received power at each time may then be compared to the equivalent map from a “quiet day”, allowing the morphology of ionospheric absorption of cosmic radio noise to be ascertained. KAIRA was used to carry out the first interferometric riometry measurements in late 2013, producing all-sky absorption maps of space weather related ionization in the D region. Full story...
Multibeam bi-static plasma parameters
In work carried out over the summer of 2013, KAIRA researchers demonstrate bi-static incoherent scatter plasma parameter profile plots. The results are in good agreement with the EISCAT Tromsø measurements, and also show for the first time that a simultaneous bi-static plasma parameter profile can be obtained using a phased array incoherent scatter radar receiver. Full story...
190 MHz BANDWIDTH
On 1st June 2013, KAIRA observed a total instantaneous bandwidth of 190 MHz, using parts of both arrays (LBA and HBA). This is accomplished by using the 4-bit mode, coupled with selective application of attenuators. While loss of some dynamic range is a problem in some cases, the availability of 190.6 MHz total bandwidth is a very attractive prospect indeed! Full story...Ionospheric Scintillation Arcs
Using KAIRA, the evolution of scintillation from weak to strong scattering regimes has been directly observed in dynamic spectra. "Scintillation arcs", seen previously in two-dimensional power spectra from interstellar scintillation observations, have been now been found for the first time. Introduction and Full story...
Long-Baseline Interferometry
On Monday 13th May 2013, joint observations between KAIRA and LOFAR station DE601 detected fringes from the pulsar B0809+74. This detection is the longest baseline to have achieved this within the LOFAR system... a baseline of some 2185 km! Full story...
Active heating effect detected
Using KAIRA data from 20 March 2013, we were able to detect the active heating of the ionosphere by the radio-waves sent from the EISCAT Heating facility. Because the ionospheric opacity is altered, this surprisingly subtle effect can be measured by KAIRA when used as a riometer. Full story...
KAIRA observing scintillation
In order to observe simultaneously at all frequencies from 30 up to 250 MHz, KAIRA needs to make use of RCU-357-mode. This is where different sets of antennas are used to cover the different frequencies. By making clever use of the selection (to optimise the beam patterns) and being very careful in the activation sequence (to avoid tripping circuit breakers), it is possible to cover such a wide range. Full story...
Electron density profiles measured
Using multi-frequency absorption measurements of cosmic radio noise, KAIRA has demonstrated the ability to use inverse-problem techniques to determine the electron density at a large range of heights. Full story...
KAIRA's first all-sky image
Although nothing new scientifically, the acquisition of the first all-sky image is an important step for the KAIRA station in demonstrating its operation capacity. These images will be used in later experiments to carry out surveys and atmospheric studies. Full story...
Mode-357
Most LOFAR stations have two antenna fields, capable of receiving a range of 10-90 and 110-270 MHz. However, the signal processing is handled differently – the so-called "mode". In September 2012, KAIRA made the first multi-mode observations. Full story...
Pulsar observations
On 18th September 2012, KAIRA made its first successful detection of pulses from a rapidly rotating neutron star. Although not a new measurement for radio astronomy, it was the first time we had demonstrated this with KAIRA... an important step in the commissioning of the system. Full story...
Detecting solar radio bursts
A five minute dynamic spectrum recorded using a single LOFAR LBA antenna element in KAIRA. Apart from the HF radio band, the most prominent features are several Type-3 solar radio bursts and the FMCW over-the-horizon radar signal transmitted from Cyprus. Full story...
Plasma parameter fit
In late August 2012, the KAIRA team developed a new analysis method for efficient side-station inversion of the incoherent scatter measurements. In this first example, we combine lag-profile inversion results from 20 different beams simultaneously pointing at different altitudes along the EISCAT VHF beam. With this configuration, we can perform a bi-static measurement simultaneously along all the different altitudes. Full story...
Lag-profile inversion
In August 2012, we managed to get fast Fourier transform lag-profile inversion working to some extent with real world signals contaminated with space debris and meteor head echoes. We can now estimate ionospheric plasma incoherent scatter autocorrelation functions and spectra with a fairly nice accuracy and computational speed. Full story...
