Load a samples.json from the Suunto app logs or the JSON export of an activity. Explore the GNSS track, altitude and estimated accuracy on one timeline, with a summary of what the data shows.
samples.json from smlzip, or the file downloaded from the Suunto app.
The demo is a 37 minute run with elevated GNSS error estimates early in the recording.
Includes EHPE, EVPE, satellites, SNR, pressure, power and battery when recorded.
/Android/data/com.suuntoapp/files/smlzip/ (or a similar folder under com.stt.suunto).samples.json.Available fields depend on the watch and activity.
Markers use recorded values at GNSS points. The summary includes all sensor samples.
No GNSS coordinates in this file.
Select a point on the map or chart to inspect its values.
Altitude, m
Estimated error, m EHPE warning threshold: 10 m
Time since start. Shading marks sustained warnings. Double-click to reset zoom.
R-R interval, ms Dots: artifacts · rings: ectopic pairs
DFA α1 Dashed lines: 0.75 and 0.5
RMSSD, ms 60 s window
Time since start. Shading marks recording gaps and stretches with more than 5% artifacts.
A beat is a recording artifact when its interval is outside 300–2000 ms or differs by more than 20% from the median of its neighbors. A long interval near twice the median suggests a missed beat. Artifacts measure strap quality.
Ectopic pairs are counted separately: a beat more than 10% shorter than the local median followed by a compensatory longer one, together about two normal beats. Occasional ectopic beats are common and strap noise can look similar. These are application heuristics, not a medical assessment.
Artifacts and ectopic pairs are both left out of SDNN, RMSSD, pNN50 and DFA α1. DFA α1 uses 2-minute windows with at most 5% excluded beats.
DFA α1 describes how beat-to-beat intervals are correlated; it falls as effort rises. Research uses these bands: above 0.75, light effort below the aerobic threshold; 0.75 to 0.5, between the aerobic and anaerobic thresholds; below 0.5, around or above the anaerobic threshold. Values near 1.0 or higher are typical of easy effort and warm-ups. Very low values (below about 0.3) can come from hard efforts but also from artifacts or ectopic beats, so check that stretch first. The bands are research averages and individual thresholds differ. α1 is most meaningful during a gradual increase in effort; with intervals or changing terrain it follows the pace. Treat it as an orientation, not a measurement.