WSPR Globe

Quick Start

1. Optionally set Receiver and/or Transmitter call signs (leave blank for “all”).
2. Choose a time window (e.g., 15 minutes) and optional Days Ago / Hours Ago offsets.
3. Select one or more frequency bands.
4. Click Load WSPR Spots.

Mobile / Small Screens

• Hide/show sidebar: use the ✕ button to close the sidebar, or the ☰ button to reopen it.
• Tip: closing the sidebar gives the globe more room and can feel faster on small devices.

Understanding What You See

• Arcs: a propagation path from TX → RX, color-coded by band.
• Markers (if enabled): solid circles are TX locations; open circles are RX locations.
• Click for details: click any arc or point to see the underlying spot info (callsigns, time, frequency, distance, SNR, power, etc.).

Search & Filters

• Call sign filters: set Receiver and/or Transmitter to narrow the search.
• Time window: the duration of the window you want to visualize.
• Days Ago / Hours Ago offsets: the window ends at “now minus (days + hours)”, and extends backward by the selected window size.
  Example: “15 Minutes” + “2 Days Ago” + “4 Hours Ago” searches a 15-minute window ending 2 days and 4 hours ago.
• Frequency bands: check/uncheck bands to include/exclude them (colors in the legend match the globe). Use All / None to quickly toggle all bands.
• Exclude callsigns starting with 0, 1, or Q: enabled by default to reduce non-amateur / odd entries; uncheck to allow them.

Display Modes

• Arc mode (default): deduplicated TX↔RX paths are drawn as arcs.
• Beacon mode: tracks a moving transmitter over time (best for a single TX).
• Heatmap mode: shows contact density (useful for “where activity is”, not specific paths).
• Time-lapse animation (arc mode): animates a sliding time window through your loaded spots using the play/pause controls and slider.

Sharing Links

Use the Share button to copy a URL that restores your current settings.

Supported URL Parameters

• rx, tx
• window (minutes), days (0–7), hours (0–23)
• maxSpots (download limit), maxLines (display limit: all/200/500/1000/2000/5000)
• bands (comma-separated: e.g., bands=14,21,28)
• animateLines, solidLines, showMarkers, heatmap, beacon
• timelapse, timelapseWindow, timelapseSpeed
• allowWeird: set allowWeird=1 to allow callsigns starting with 0/1/Q
• autoLoad: autoLoad=1 loads automatically on page open

Notes: the Share button currently does not add autoLoad=1 (you can append it manually if you want auto-load). The day/night terminator toggle also isn’t included in shared URLs.

Performance & Rendering Notes

• Too many lines can get slow: if rendering is choppy, reduce Max Lines to Display first (this directly reduces draw calls). Reducing Max Spots to Download also helps.
• Other speed knobs: turn off Animate lines, Show TX/RX markers, and/or Heatmap mode.
• Day/night terminator caveats: the terminator uses a transparent overlay shader and may cause subtle rendering artifacts (e.g., “rays” flickering at the darkness edge on some GPUs/browsers). It can also make the heatmap look odd because the night overlay tints/darkens what’s beneath. If you’re evaluating heatmap intensity, consider turning the terminator off.