Fig. 3
From: NetPICOmag: A low-cost networked magnetometer and its applications
Magnetograms showing B X , B Y , and B Z components from January 12, 2009 at Athabasca, Alberta, Canada. The lower trace in each chart shows data gathered from a calibrated SMALL 1 Hz fluxgate magnetometer. The upper trace shows data from a NPM unit that has been offset by 18 nT to enhance readability. The bulge appearing between 14:00 and 00:00 UT is due to diurnal effects on the magnetic field.