What is Kp index (geomagnetic activity)?
The Kp index measures geomagnetic activity on a 0–9 scale. High Kp values (5+) can interfere with drone GPS, compass calibration, and radio transmission. Most consumer drones recommend not flying when Kp > 5.
The Kp index is a planetary-scale measure of geomagnetic disturbance, updated every 3 hours by NOAA Space Weather Prediction Center. Values 0–4 indicate quiet conditions; 5+ indicates a geomagnetic storm.
For drones, high Kp affects: • GPS lock — multi-satellite constellation may degrade or be lost • Compass calibration — magnetic-field reference becomes unreliable • Video transmission — RF interference at high Kp • Battery performance — secondary effect through altitude and temperature
Most consumer drones (DJI in particular) recommend not flying when Kp ≥ 5. UAV Forecast and similar weather tools surface Kp prominently. Altoa surfaces Kp in airspace checks during active geomagnetic events.
Kp peaks typically last 6–24 hours. After a major event, the index returns to quiet within a day. The 11-year solar cycle drives long-term variation; we're currently near a solar maximum (active Kp years).
What this means for pilots
Check Kp before flight, especially during solar maximum years (we are now). If Kp ≥ 5, postpone non-critical flights. If you must fly, expect degraded GPS and prepare for manual recovery.
FAQ
Where can I check Kp?
NOAA Space Weather Prediction Center (swpc.noaa.gov), UAV Forecast, or any drone-specific tool. Altoa surfaces it in airspace checks.
What happens if I fly at Kp 6?
Possible: GPS loss, compass errors, drone enters ATTI (manual) mode, video transmission glitches. Recoverable if you're prepared but stressful.
Does Kp affect ground-controlled drones?
RF transmission is affected — same as other RF systems during geomagnetic storms. Moderate Kp (4–5) is usually negligible.
Related terms
FAA regulations change. Verify current rules at faa.gov/uas before relying on this article for flight planning. Altoa is not the FAA.