Hourly NAP Charts
Documentation on how SWS creates real time NAP charts and their use is available: SWS NAP Chart Construction (or PDF). The Best Usable Frequency (BUF) NAP is a new product that includes customer antenna type (propagation angle), required percentage of days and signal to noise ratio into the prediction. The BUF NAP shows the strongest predicted frequency compared to the real time Maximum Usable Frequency (MUF) NAP showing the highest supported frequency. There can also be differences between the two products particularly around dawn and dusk, when the ionosphere is changing rapidly, as the BUF and MUF NAP charts are currently generated at different times within the hour.