Propagation
lab
A WSPR pico balloon is a beacon at a known place, 12–13 km up, that drifts around the globe. Every frame is decoded by dozens of stations. Here you can replay who heard each frame, how far it went and how the openings follow the day and night across the planet.
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When does the band open, and towards where?
Receptions by hour of day (UTC) and the receiver's continent. Darker = more stations. Red bars: farthest reception in that hour. The red frame follows the frame shown on the map.
How far does 20 m go from 12 km?
Distance between the balloon and each receiver at the time of the frame.
Balloon vs weather model
At float the balloon simply drifts with the wind, so every pair of fixes is a wind measurement 12–13 km up. Here it is compared with the two big global weather models, the American GFS (used by the SondeHub predictor for our trajectory forecasts) and the European ECMWF, at the same place, time and height. Which one knows the jet stream better?
Segments of 40–120 minutes between fixes above 8 km (a 6-character locator is good to ~5 km, so shorter segments would add ±40 km/h of noise); jumps faster than 400 km/h (GPS spoofing) are skipped. GFS and ECMWF IFS (0.25°): Open-Meteo historical forecast API, interpolated between pressure levels by geopotential height.
A beacon in the stratosphere
The SQ9GOL tracker sends WSPR with about 10–20 mW from a solar panel, only in daylight, every ten minutes. Its position comes from GPS and is known to a few kilometres.
Hundreds of amateur stations decode WSPR and upload their spots to the WSPR network. This page reads them from wspr.live and keeps only frames that match this flight's channel and a known position of the balloon.
Long paths along the grey line (the edge of the night shading), Europe opening in the morning, the Americas in the afternoon, and how 12 km of height lets a few milliwatts cross whole oceans.
Want to be on the map? Set WSJT-X to WSPR on 14.0956 MHz USB with “Upload spots” on. Data: wspr.live (WSPRnet spots), track: SondeHub / SQ9GOL server, map © OpenStreetMap.