One of the things I’m quite interested in is recording space weather or „auroral chorus“ with a ELF/VLF receiver.
This space weather is electrically charged particles coming from the sun into the upper atmosphere, the same ones that form the northern lights, or Aurora.
The receiver therefore only detects radio frequency on a very long wavelength or at 20hz up to 20Khz
The problem, however, is that I have never been able to devote enough time to this hobby. So I don’t have many recordings of this material.
It is not enough to have a lot of equipment. I really need to have knowledge of the subject to get what I want. To be in the right place and time when events happen in the solar system and in the Earth’s thermosphere. In addition, I am always busy not letting technical ignorance affect the quality of recordings, so knowing antenna theory and receiver design is also important. But in antenna studies I know nothing, especially because of my poor math skills.
Due to lack of time, I did not even build the tuner, which is though very simple, so I bought a tuner from Stephen P McGreevy. That receiver is made for two loop antennas, so it is possible to record in stereo.
Through poor skills, I have prepared two types of antennas. One is built according to Stephan’s specification, which is nice in many ways, but takes on too much wind which sometimes interferes with the recording. Then I have make another one that unfortunately produces (or receives) a lot of „pink noise“. But that antenna is fast to set up and very convenient for finding the right X/Y axis for stereo recording.
But not everything is counted. As well as air and noise pollution from people, there is also an enormous amount of strong electrical pollution everywhere in human settlements, literally in all frequency ranges. So I also need to find places where there is little or no electrical pollution. I’m also not allowed to be near tall trees or high mountains. High voltage lines, radio transmitters and electrical fences must be many kilometers away. It therefore puts a lot of strain on patience and long journeys that are often fruitless. I therefore try to use the time I use for nature recordings to record simultaneously VLF space weather recordings.
It was just the other day that I discovered a place incredibly close to Reykjavík that was remarkably free of electrical pollution, as well as a request from a composer and two musicians for a recording, that made me see if I could pull out the equipment and start recording something. Probably make better antennas.
But as the sun is quite calm these days, actually these months and years according to the „annual solar cycle„, it could be a difficult task to get a good recording.
Therefore, here is a recording from mid August 2017, recorded at Skeiðarásandur south east Iceland. The recording location is far from mountains and human settlements, several kilometers from the nearest high-voltage line or electric fence . It was therefore relatively easy to clean electrical pollution from the recording. However, you can see in spectrogram (and hear) various weak radio signals and pulses, but most of them are above 15Khz.
This is not a „strong“ recording. In a real solar storm the „sparking sound“ is more powerful with more depth and colorful sounds. My favorite sound in space weather recordings is „Whistler„. I have only heard it once with my equipment, but Iceland is actually not located on the best latitude.
(mp3 256Kbps / 60,8Mb)
Recorder: Olympus LS10
ELF/VLF Receiver: WR-9STL
Antenna: Two 3 meters high triangle loops, X/Y setup on carbon fiber boom pole
Location: 63.970253, -17.160061
Weather. Calm, dry, cloudy
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