By Jari Perkiomaki OH6BG

I am happy to announce a new service which offers 18,000+ propagation charts for you to explore how signals propagated between two user-selected ITU zones in 2018. The raw spot dataset was received from HamSci, including approximately 8 billion FT8 spots that were collected from sources such as PSK Reporter during the entire year of 2018. There are data from 6 meters to 160 meters. The heavy-lifting, i.e. data processing (incl. pre-processing such as data validation) and data visualization for the charts, has been done by Alex Shovkoplyas, VE3NEA.


The charts show the scaled number of spots in different colors over the 24-hour period over the 12 months. Also plotted on the charts are the sunrise and sunset timelines, calculated for “the center of mass” of the callsigns in each ITU zone. This will make it easier, for example, to distinguish enhanced periods of propagation on low bands at sunrise/sunset, something which VOACAP is heavily underpredicting. Furthermore, on the top part of the charts, you will see the development of the planetary A index (Ap) over the year of 2018, and see how increased Ap indices will affect propagation – high Ap indices are not always a sign of decreased conditions!

I think this unique set of charts will give the ham community all over the world new and surprising insights into HF propagation! If you have questions, please write to [email protected].