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WSPR — Weak Signal Propagation Reporter

WSPR (pronounced "whisper") uses highly compressed digital transmissions at roughly 200 mW to probe HF propagation paths. Stations transmit a 2-minute beacon containing callsign, grid square, and power level. Receiving stations decode these beacons and report the measured SNR to wsprnet.org.

Because WSPR uses such low power, a decoded spot means the path is open at the propagation floor — not just open for high-power voice, but open enough to carry a minimum-power digital signal. This makes it the most sensitive propagation measurement in the dataset.

11.48B spots. 18 years. One of the largest amateur radio propagation datasets of its kind.


Dataset Statistics

Metric Value
Total Rows (wspr.bronze) 11.48B
Date Range 2008-03-11 to 2026-05-22
Daily Spot Rate (recent) ~7M spots/day
Unique Transmitter Callsigns 4.0M
Unique Receiver Callsigns 100,792
Unique Grid Pairs 8.3M
Bands Covered 160m–10m (10 HF bands)

Band Breakdown

Band ADIF ID Spots Pct of Total
160m 102 199.3M 1.74%
80m 103 867.0M 7.55%
60m 104 130.2M 1.13%
40m 105 3.68B 32.01%
30m 106 1.93B 16.77%
20m 107 3.10B 27.03%
17m 108 431.3M 3.76%
15m 109 419.4M 3.65%
12m 110 126.5M 1.1%
10m 111 338.7M 2.95%

Band IDs are ADIF standard. Band assignment uses frequency-to-band lookup (single source of truth in bands.GetBand()). Fixed as of v2.1.0 re-ingest (2026-02-03) — all rows carry correct ADIF IDs.


Data Quality Notes

  • SNR range in raw data: -99 to +60 dB. Real WSPR is typically -30 to +20 dB.
  • Ground-wave spots (< 500 km) are present in bronze but filtered from signatures to focus on ionospheric skip.
  • Balloon/telemetry callsigns removed: 1,443 entries identified in wspr.balloon_callsigns_v2, covering ~950K spots (0.009% of bronze).
  • 93.6M rows promoted to wspr.signatures_v2_terrestrial after quality filtering and solar joining.