Sodankylä Geophysical Observatory |
Description
SGO pulsation magnetometer stations (01/2021):
Finnish pulsation magnetometer chain includes eight two or three-component search coil magnetometer stations. The most of the stations are nearby the IMAGE magnetometer stations, which sampling limits to 1Hz. Pulsation magnetometer stations locates in Sodankylä, Kevo, Kilpisjärvi, Ivalo, Rovaniemi, Oulu and Nurmijärvi in Finland and Abisko in Sweden. Instrument upgrade to 250Hz system is going on and most of the station runs today with 24-bit 250Hz sampling with cut-off filter at 35Hz. 250Hz stations are capable to monitor Alfven resonators and Schumann resonances in addition to regular geomagnetic pulsations (Pc1-2, Pi, ipdp). Timing of the data based on the GPS PPS with 10MHz reference. Part of the stations (SOD,IVA,ROV) are still running old 40Hz system which was taken into use in 2002-2003. This upgrade with new coils increased the cut-off frequency 10Hz (3dB point) bringing 1st Schumann resonance possible to monitor. However, the signal noise ratio at lower band was weaker than earlier, only the strongest Alfven resonators were detected. 40Hz stations are timed by GPS PPS and sampling rate of the data is 40Hz. 40Hz instrument was deployed to Barentsburg in July 2005 in co-operation with Polar Geophysical Observatory, Russia and University of Leicester, UK. Part of the instrumentation of Barentsburg station was destroyed in the fire at the observatory building in January 2010.
| station | start of operation | geographic co-ordinates | L-val. | Comp | timing | AD converter | sampling |
|---|---|---|---|---|---|---|---|
| KEVO | 11/2018- | 69.75°N 27.02°E | 6.5 | XY | GPS PPS +10MHz ref | 24-bit | 250 Hz |
| KILPISJÄRVI | 9/2015- | 69.05°N 20.79°E | 6.2 | XY | GPS PPS +10MHz ref | 24-bit | 250 Hz |
| KILPISJÄRVI | -11/2015 | 69.02°N 20.86°E | 6.2 | HDZ | GPS PPS | 16-bit | 40 Hz |
| ABISKO | 07/2019- | 68.40°N 18.90°E | 5.6 | XY | GPS PPS +10MHZ ref | 24-bit | 250 Hz |
| IVALO | 68.55°N 27.28°E | 5.5 | HDZ | GPS PPS | 16-bit | 40 Hz | |
| SODANKYLÄ | 06/2018- | 67.43°N 26.39°E | 5.4 | XY | GPS PPS +10MHZ ref | 24-bit | 250 Hz |
| SODANKYLÄ | 67.42°N 26.39°E | 5.1 | HDZ | GPS PPS | 16-bit | 40 Hz | |
| ROVANIEMI | 66.78°N 25.94°E | 4.8 | HDZ | GPS PPS | 16-bit | 40 Hz | |
| OULU | -07/2020 | 65.08°N 25.90°E | 4.3 | HDZ | GPS | 16-bit | 40 Hz |
| OULU | 08/2020- | 65.08°N 25.90°E | 4.3 | HDZ | GPS PPS +10MHz ref | 24-bit | 250 Hz |
| NURMIJÄRVI | -12/2019 | 62.42°N 25.28°E | 3.7 | HDZ | GPS PPS | 16-bit | 40 Hz |
| NURMIJÄRVI | 12/2019- | 62.42°N 25.28°E | 3.7 | HDZ | GPS PPS+10MHz ref | 24-bit | 250 Hz |
Station coordinates and related other instrumentation can be found here.
 |
| Location of the Finnish pulsation magnetometer chain (01/2021). |
|---|