An Atlas of what HamSCI’s Personal Space Weather Station Doppler Spectrograms show

Welcome to this guide on the interpretation of HamSCI PSWS Doppler Spectrograms.

We encourage contributions from operators of all types of HamSCI network Personal Weather Stations. Please contact Gwyn Griffiths (G3ZIL) if you have examples to be considered for addition to the atlas.

Conceived of by Bob Mattaliano (N6RFM), this work was first presented as a poster at the HamSCI 2026 conference together with co-authors Gwyn Griffiths (G3ZIL), Gary Mikitin (AF8A), Dave Swartz ( W0DAS), and Mary Lou West (KC2NMC). Credit to Gwyn for creating this Read The Docs style repository!

Introduction

New to HamSCI Personal Space Weather Station Doppler Spectrograms? Or an old hand but intrigued by some of the peculiar features? Check out the events and features from the Atlas.

You can delve straight into the features, or you may want a refresh on the Principles of Operation in the summaries below.

Spectrogram Interpretation

• The Ionosphere and HF Propagation
  • Overview
  • D Region (roughly 35–55 miles / 60–90 km up)
  • E Region (roughly 60 miles / 90–150 km up)
  • F Region (roughly 100–300 miles / 150–500 km up)
  • Why F Splits into F1 and F2
  • What You See on a Grape Spectrogram
  • Further Reading

Principles of Operation

• GRAPE-1
• GRAPE-2
• WSPRDaemon GRAPE

Feature Spectrograms

• Typical Spectrogram
• Surface Wave
• One-hop E region propagation
• Sporadic E (Es)
• One-hop F Region Propagation
• Two Hop F Region Side Scatter
• Prolonged Two Hop F Region Side Scatter
• Dawn Doppler
• Travelling Ionospheric Disturbance
• SID and Doppler Flash
• Solar Eclipse
• BPM Time Signals
• High and Low Rays

Event Spectrograms

• Partial Eclipse 29 March 2025
• Geomagnetic Storm 18 January 2026

Artifacts

• Precision Local Oscillator

Resources

• Event Template
• Lexicon