VHF Propagation Map
VHF Propagation Map. This map shows real-time radio propagation from stations ... Paths are smoothed to create a color-coded footprint indicating the distance VHFÂ
This map shows real-time radio propagation from stations operated near 144 MHz. It uses data gathered by Automatic Packet Reporting System-Internet Service (APRS-IS) from packet stations in the amateur radio service.
The map shows activity from the past hour. Paths are smoothed to create a color-coded footprint indicating the distance VHF signals are likely to be traveling. Packet stations typically run low power into small vertical antennas. Better equipped stations should exceed the the distances these stations report. The map is updated automatically, up to several times per minute.
The map is created using positions (latitude and longitude) reported by nodes in the packet radio system and the hops that are recorded as the packet travels from node to node. The distance between each end of a hop is the basis for the display drawn on the map.