Explore the 50,000+ real-life propagation charts from one ITU zone to another ITU zone over the months of 2017-2019! The raw data comes from the nice people at HamSci, courtesy of Bill Engelke, AB4EJ, and Philip Gladstone, N1DQ. The heavy-lifting, i.e. data processing (incl. pre-processing) and data visualization, has been done by Alex Shovkoplyas, VE3NEA.

There are a number of features in the charts:

• The top area the Ap (planetary A) index. You will see the effect of Ap values to the propagation.
• Yellow line the solid line shows the sunrise time in the First Zone. The dotted line is the sunset.
• Red line the solid line shows the sunrise time in the Second Zone. The dotted line is the sunset.
• The chart pixels the colors represent the absolute spot counts on the log scale so that it is possible to compare the different charts. The formula is color = Log2(count), i.e., 1 -> color0, 512 -> color9. In other words, red shades indicate high counts, blue shades low counts.

The sunrise and sunset times have been calculated for "the center of mass of the callsigns" in each ITU zone, shown as a red circle on the ITU Zone Map below.