| Do you want to know if the VHF bands are open? Take a look at this hourly updated map to find out. |
This map shows actual 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 that has happened in the past hour. Paths are combined to create 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, typically several times per minute. The map is created using positions (latitude and longitude) reported by nodes in the packet radio system and the hops from node to node that the data travels. By correlating the hops with the position of each end of the hop, the distance can be inferred.