The above calendar displays "readability" by color coding; i.e. days with coded red most stations have readability of 5, days without color coding (black) are days when station readability by was 0.
In efforts to correlate Eielson AFB and Gakona ionosonde with polar region propagation on 75 meters, this study compares station transmissions from audio recordings made during a daily 75 meter net with ionograms for the same time period.
On each page a a 30 minute recording sample taken from the Snipers Net is set for comparison with ionograms for the same time period. After the net, ionograms are compared to station locations (Net Roster) to determine whether stations were strictly ground wave or heard by propagation.
So far, recordings with only local ground wave transmissions correlate to ionograms without ionospheric reflection, but transmissions from stations outside the ground wave zone correlate with ionograms showing clear ionospheric signal reflections; thus correlating digisonde ionogram reflections with 75 meter propagation.
As becomes obvious, hams in the far north must have greater long suffering and patients to continue enjoying the hobby; not uncommon to wait for a week for conditions that make the hobby worth while. During the boring flat line days without it's not uncommon to find hams diddling with US Air-force ionospheric data plots to stay temptations to sell their gear for a bellydancer’s bellybutton lint collection.