Scientific Instrument / Dark Lab

HF Propagation Lab

A browser-only teaching instrument for amateur radio operators. It explains what live space-weather numbers suggest, how each band may react, and which ionospheric mechanism is probably doing the work. It is a teaching model, not a substitute for beacons, skimmers, WSPR, or listening on the air.

Five Layers of Propagation

    Open student exercises

    Last updated Loading live data…
    Data freshness Checking cache and live feeds
    Auto refresh in --:--
    Forecast glance Awaiting forecast feed
    Your station
    DX station
    No station location set. The page is currently using a global/UTC approximation rather than your local solar conditions.
    Provide a station Maidenhead grid or allow browser geolocation to switch to station-aware sunrise, sunset, local solar time, and path-sensitive scoring.
    Propagation Weather Report

    Global Conditions Summary

    Loading live solar and geomagnetic data…

    Right Now UTC

    Operating Window

    Building a diurnal snapshot from current time and conditions.

    Recent Alerts

    Storm Watch

    Checking NOAA alerts and warnings.

    Live Gauges

    Kp Gauge

    Geomagnetic Activity

    SFI Gauge

    Solar Flux

    45-Day Trend

    Solar Cycle Context

    Loading observed solar-cycle data.

    Band-by-Band Ratings

    Which bands are likely to work, and why?

    The score combines live solar flux, Kp, X-ray conditions, Bz, solar wind, station-aware local solar time when available, rough path class, and hemisphere-aware sporadic-E seasonality. Each card explains the drivers, but the score is a teaching estimate. It is not a measured path MUF, not a ray trace, and not a promise that your antenna will work.

    No station grid is set. Day/night-sensitive ratings are deliberately conservative until you enter your grid, because UTC is not local daylight for most of the world.
    Skip Zone / Hops

    Why Nearby Stations Vanish

    Grey-Line Indicator

    Twilight Can Open Low Bands

    Near sunrise and sunset, the D-layer decays quickly while higher ionization can remain. That lower absorption can briefly enhance 160m, 80m, and 40m long-haul paths.

    Time-of-Day Overlay

    Right now it is --:-- UTC

    Computing day/night absorption and F-layer support.

    Solar Cycle 25

    Cycle Context

    Loading observed and predicted Solar Cycle 25 context.

      Forecast Outlook

      NOAA 45-Day Outlook

      Waiting for forecast data.

        How The Model Reasons

        Why The Page Says What It Says

        Explaining which inputs are measured directly, which are inferred, and how they are used to build the band ratings.

        Verify On The Air

        Do Not Worship The Dashboard

        The model is only the classroom guess. Before claiming a band is open or closed, compare it with WSPR, PSKReporter, Reverse Beacon Network, NCDXF/IARU beacons, DX cluster spots, and ordinary receiver noise. Then ask whether your antenna takeoff angle, height, polarization, local noise, and power match the path you are testing.

        • Measured data: SFI, Kp, X-ray flux, solar wind, alerts, and forecasts.
        • Inferred teaching model: rough band score, local solar time effects, path class, hop count, and MUF clue.
        • Operator verification: tune the band, check beacons/skimmers, call CQ, and log what actually happened.
        Live Solar Image

        SOHO EIT 284 Corona

        This extreme-ultraviolet image shows the hot solar corona, including coronal holes and loop structure. It is useful context for solar activity, not a direct band-opening predictor and not a white-light sunspot image; sunspots are photospheric features.

        Latest SOHO EIT 284 angstrom extreme-ultraviolet image of the solar corona

        Metric Details

        Glossary / Physics Primer

        Terminology You Hear on the Air

        Open any term for a plain-English definition and why it matters on HF.