VHF Propagation Map

View map — Proceed to the propagation map. Javascript must be enabled in your browser, or use the text only interface.

The most active areas are typically the eastern US, Colombia, Europe, eastern China, and sometimes Japan.

For VHF propagation predictions use William Hepburn's tropospheric ducting forecast. For details about specific packet radio stations see aprs.fi.
About — The VHF propagation map highlights real time radio conditions with enhanced distances between stations operating near 144 MHz. The map is based on data gathered by the Automatic Packet Reporting System-Internet Service (APRS-IS) from packet radio stations in the amateur radio service.

Typical local propagation is shown with greens and yellows. Enhanced distances appear as shades of orange to red.

News

2 Jan — A "Home" menu was added to the map menu, that returns the user to the starting page. Contact information was moved from the map menu to the start page.

1 Jan — Position changes are noted in the browser history. This allows going back to previous positions and bookmarking.

30 Dec — A landing page that provides basic information about the site is now the point of entry. The purpose of this page is to provide a quick overview, offer a variety of entry points, and highlight the technology behind the map. The page is designed to load very quickly and avoid loading the bulky scripts and map tiles if the visitor does not intend to proceed farther.

20 Dec — added an optional "center" URL parameter to initially the map. Example: "vhf.dxview.org?center=47.19,10.12,6.3" - paramaters are degrees latitude, degrees longitude, and zoom level (0.0-10.0).

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Station Details — Information about stations and their connections can be accessed in this way:
  • Touching or hovering over a footprint will highlight the border and reveal its idenity.
  • Selecting the identity label will pop up more detailed information.
  • Touching or selecting a previoiusly highlighted station will draw spokes that summarize the direction and distance of stations heard. A detail menu of other selection options appears at the top of the map.
  • When detail menu option multiple is selected, station selections accumulate, revealing their interconnectinos. A keyboard shortcut using alt- or option-click is equivalent
  • When detail menu option connected is selected, station connections in the region are revealed and identity labels are surpressed. A keyboard shortcut using c-click is equivalent
Amateur Radio — The amateur radio service consists of trained and licensed volunteers authorized to transmit within designated bands across the radio spectrum. The service operates under an international agreement and licensing requirements vary from country to country. Typically there is no minimum age requrirement. Each operator or station is issued a unique callsign that identifies the transmitting station and the country of origin.
Contact — Feedback may be provided via:
Technologies — this site relies on open-source software and commercial hosting:
  • OpenStreetMap: the map layer.
  • OpenLayers: the map interface library.
  • MariaDB: data storage.
  • Apache HTTP Server: web server.
  • Squid: web delivery optimizer.
  • Rust and its crates: the software that ties it all together.
  • Google Compute Engine: provides the CPU and web presence.