What this page measures
This page analyses the
reported receive frequencies of decodes from the PSKReporter “Live” feed for
M7SQI.
Decodes are grouped into short time windows (default
15 s). For each window it derives
simple frequency statistics that describe how the reported values behave over time:
- IQR (Hz) — interquartile range of reported receive frequencies (how tightly the reports cluster).
- Δ median (Hz) — the window median relative to the overall median for the selected period (a frequency residual).
- n/window — number of decodes contributing to that window (sampling strength).
How to read it
Low IQR combined with a stable Δ median indicates a tight and internally consistent set of reports.
Rising IQR reflects a broader mixture of receivers, frequency offsets, and/or propagation paths.
Changes in Δ median may occur because the reporting population changes and/or because the effective propagation geometry
evolves (for example due to changing reflection height or which regions are open).
Experimental context
This page was originally conceived as an attempt to observe Doppler-like effects associated with ionospheric motion.
In practice, PSKReporter data combines contributions from many receivers with differing frequency references and calibration offsets,
and these effects dominate when transmissions are intermittent or reporter populations change.
The quantities shown here therefore represent frequency residual statistics, not direct Doppler measurements.
Omnidirectional viewpoint
This is not a single fixed raypath. M7SQI illuminates many directions simultaneously, and the aether decides who hears it.
The plotted statistics therefore represent a population-weighted view of all active paths at that moment,
rather than one chosen great-circle path.
Background shading
Kp is shown as a subtle always-on backdrop: green = quiet (Kp<3), amber = unsettled (Kp 3–4),
red = storm (Kp≥5). This provides geomagnetic context only and does not directly indicate propagation quality.
Interpreting Δ median as a response proxy
When Δ median is informative
When transmit frequency is fixed and the reporting population remains reasonably stable,
coherent changes in Δ median can act as a
proxy for propagation-related frequency response,
including Doppler-like behaviour caused by changing reflection height or path length.
What to look for
- Smooth drifts or arcs — consistent with slow layer rise/fall or large-scale plasma motion.
- Quasi-periodic oscillations — consistent with traveling ionospheric disturbances (TIDs).
- Jumpy or discontinuous behaviour — more likely dominated by changing reporter mix and station offsets.
Why SWPC overlays help
GOES X-ray flux and solar-wind magnetic field data provide context for external forcing.
The frequency residuals reflect the medium’s response.
Agreement in timing supports a propagation-driven interpretation, but does not by itself prove causation.