Laurentian University Radio Observatory
Live data from Sudbury, Ontario, Canada
Maintained by Kevin Saroka

Coordinates 46.49 N, 81.01 W (click here for location on Google map)

ULF Induction Magnetometer-Magnetic Field

The magnetometer is situated in a quiet area on the Laurentian University campus in Sudbury, Canada.  Data is streamed continuously to a laptop placed inside of the pump house which houses the sprinkler system for the Laurentian University soccer field approximately 50 m from the magnetometer using standard 2-channel microphone cabling.

The magnetometer consists of approximately 96000 turns of AWG 28 copper wire with steel welding rods inserted to increase permeability and is modelled after Hans Michlmayr s design (; it is housed in a wooden crate along with dry sand to maintain stability and oriented to receive the N-S component.  The input is fed into a Minimal Loop preamplifier designed by Renato Romero (  

Map showing location of Sudbury, Ontario, Canada

Wooden crate housing

during early stages of winding
Minimal Loop preamplifier system, designed by Renato Romero

ULF magnetic field

Below is a spectrogram updated every 5 minutes displaying the last 8 hours of activity between 0.1 and 50 Hz.  Bottom part is 0-4 Hz.

Scroll time 40 seconds, FFT frequency resolution 21 mHz

Magnetic field hourly multistrip shows ULF activity within the 0.1 to 5 Hz range showing last 6 hours.  Useful for detecting events of short duration in the frequency range of Schumann Resonances.  Data is updated every 15 minutes.

Scroll time 4.6 seconds, FFT frequency resolution 168 mHz

Magnetic field daily multistrip shows 0-40 Hz activity of the last 6 days.  Updated every hour.

Scroll time 109 seconds, FFT frequency resolution 5 mHz

Magnetic field daily multistrip shows 0-10 Hz activity of the last 6 days.  Scroll time is 110 seconds and is updated every 15 minutes.  Useful for checking the occurrence of geomagnetic pulsations, onsets of geomagnetic storms, and spectral resonance structures (SRS).

Scroll time 109 seconds, FFT frequency resolution 5 mHz

ELF - Electric Field 

Marconi antenna; 3m tall 10 m wide top hat equipped with LNPF-24 preamplifier designed by Renato Romero. Gain set at +24 dB and 0-100 Hz filter turned on

LNVA_24-20 Low noise voltage Amplifier, basic circuit. I adopted the version with AD820 very low current noise operational amplifier, as reported here LNVA.pdf

0-15 kHz reception. Picture updated every 5 minutes. Scroll time 40 seconds, FFT frequency resolution 21 mHz.

0-105 Hz reception.  Picture updated every 5 minutes.  Schumann resonances are almost always visible. Scroll time 40 seconds, FFT frequency resolution 21 mHz

0-50 Hz daily multistrip.  Scroll time 109 seconds, FFT resolution 5 mHz.  Updated every hour.

Unattended operations and spectrograms are perfomed with SpectrumLab:  Extra special thanks go to Renato Romero for his patience and help in constructing the magnetometer and antenna system and for hosting the data on

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