Why GPS is Affected
GPS relies on signals from satellites passing through the ionosphere. The ionosphere refracts and delays the signals; receivers (and networks) correct for this using models. During geomagnetic storms, the ionosphere is disturbed: electron density and structure change, so the corrections are less accurate. Result: position errors (sometimes meters to tens of meters) or loss of lock in severe cases.
Scintillation
In some regions (especially high latitudes and equatorial), storms can cause scintillation—rapid fluctuations in signal strength—which can degrade or interrupt GPS. Aviation and maritime users may see reduced accuracy or outages during strong storms. Forecasts (e.g. NOAA SWPC) help operators plan. Cosmic Radar shows Kp so you can see when storm conditions may affect GPS.
Sources and further reading
- NOAA – GPS and space weather – Ionospheric effects on GPS
- ESA – Ionosphere – Ionospheric disturbances