Live Demo — Synthetic Magnetometer

Simulated data

Runs entirely in your browser — no hardware required. Synthetic data in the NextMAG live-feed format, processed by a real FFT spectral engine.

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Total field (Bt)

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dB/dt (1-min)

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Dominant freq

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GIC risk

0normal

LineRate

FFT spectrum — amplitude (dB re 1 nT) vs frequency (Hz)noise floor —

Toggle Grid EMI to see the mains fundamental and its harmonics appear; switch 50/60 Hz to watch the comb shift. "Inject spike" adds a broadband transient; "storm" raises the noise floor.

Spectrogram — frequency (vertical, 0–320 Hz) over time (scrolling →)

Horizontal bands are the mains harmonics; toggling 50↔60 Hz or storm mode shifts/raises them in real time.

Total field (nT)

Rate of change dB/dt (nT/min, 1-minute cadence)

Computed as |Bt(t) − Bt(t−60s)| per NOAA/NERC convention (thresholds like 10/30/100 nT/min assume 1-minute sampling), so it reads 0 for the first minute while a baseline accumulates. Quiet conditions sit at a few nT/min; storm mode drives it — and the GIC (geomagnetically induced current) risk score — up.