This page is for prototype data, instruments, and software. Usually I'm just testing that gadgets are recording and displaying whatever data they're receiving. While this is happening, I'm also looking to see if there are any common trends appearing, especially during space weather events.
Frankencoil 2 being constructed.
|Frankencoil 2 being tested.|
Frankencoil 2 is an prototype air-core induction magnetometer. The idea is that a large coil with a high number of turns will generate a voltage in a changing magnetic field. In theory geomagnetic disturbances caused by space weather should be detected.
Frankencoil is made from 4 boxes of network cable, wound into a loop three metres in diameter. All of the wires in the network cables are soldered together to create a single giant scramble-wound coil of about 1000 turns. This coil is then wrapped in an earthed skin of aluminium mesh which dampens the sensitivity to radio-frequency signals, but allows the changing magnetic field to be recieved. Frankencoil has an effective area of 7200m2.Because Frankencoil lays on the ground, it is most sensitive to the vertical component of the Earth's magnetic field.
The signal from Frankencoil can then be fed into simple electronics to filter out noise, amplify the signal etc, before being fed into the Mic-in of a computers sound card. We use a free signal processing software package called Spectrum Lab to filter and display the data and to generate CSV files which we process with custom software to create the following graphs and plots.
The biggest challenge with using a device like this is the amount of electromagnetic pollution from domestic power. A rural location would be much quieter, but in the meantime I am interested to see if there is anything that can be detected with Frankencoil that can be linked to space weather.
In most of the experiments that follow, I try to find ways to bypass or use the problem of electromagnetic pollution.
Activity from a standard magnetometer. Look for spikes in the experiments that co-incide with magnetometer activity.
Raw broadband count of sferic noise. Most of this is lightning strikes within a 1000km or so. There is a possibility that the rate of sferics is affected by space weather events, so this experiment is designed to see if our 1000 turn shielded coil can detect this.
This is a measure of background noise in two broad bands - 4.8kHz and 8kHz.
The idea here is that if we can't track the direct effects of space weather on the magnetic field, maybe we can observes it's effects by proxy, on the noise in the power network. There has been research that looks at the effects of geomagnetically induced current in power grids during space weather events. One of the effects is the increase in strength of certain harmonics in the 50Hz mains "hum" when space weather hits the Earth. This experiment looks at frequencies that seem particularly suceptible to this effect, and watches them to see if there is a change in their amplitude during a magnetic storm. So far this experiment has produced ambivalent results.
This is a spectrum of VLF noise from zero to 100 hertz. In theory, low frequency magnetic noise that occurs during space weather events should be visible. In practice, the urban location of Dunedin Aurora means that domestic mains noise drowns out everything. However this is a chance that during strong CME and solar wind events, something could be visible above the hum. Look for dark, diffuse blobs and patches in the spectrum under 50Hz, that are not mirrored above 50hz.
It is also possible that harmonic noise may increase during a space weather event due to induced voltages in the local power grid. This may appear as addition dark horizonal lines at certain frequencies that appear at the onset of a magnetic storm, or CME.