Ionospheric Sounding Study

DPS-4D EI764 064 / 64.630750, -147.042904

Propagation for Snipers Net 3920 KHz 0200 UTC





  5 4 3 2 1 0
Su M Tu W Th F Sa
  28 29 30 31 1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30


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.

Polar Cap Absorption Animated
Be advised date and time from NOAA and Lowell Digisonde are recorded as UTC but data for net recordings are published locally being 8 hours behind UTC.  



Ambient Background Noise Samples

(Collected From Mobile Station Recordings on September 23, 2017 Fairbanks Alaska suburban and surrounding off-grid bush areas.)


These recordings were made with an Icom IC-7100 internal digital recorder, setting for which cannot be altered; therefore, these recordings are made at standard recording sensitivity. To appreciate the full benefit, set your volume for Bush sample, then without changing the volume check suburban sample.

Remote Bush Site S 0-1 Suburban Site S 5-6 Two Sec Alternating Sample Comparison
Lesson Learned: Before buying real estate, it wise to perform an rf ambient noise level check, to save you from depending on other stations in quiet areas from baling you out when you miss weaker signals. 


Ionosonde Data Source Currently NOT ACCESSABLE

IRI Real-Time Assimilative Mapping (IRTAM)

Global Near-Real-Time F2-layer Critical Frequency and Peak Height