DPS-4D EI764 064 / 64.630750, -147.042904

Propagation for Snipers Net 3920 KHz 0200 UTC (Net Roster)

Receiver Audio Location - 64.6 / 147.4


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B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-13 over the past 24 hours, was
above S-scale storm level thresholds.

Solar Radiation Storm Forecast for Sep 13-Sep 15 2017

              Sep 13  Sep 14  Sep 15
S1 or greater   95%     80%     60%

Rationale: The greater than 10 MeV proton flux is expected to continue
at S2 (Moderate) levels early on day one (13 Sep), then decrease to S1
(Minor) later in the day as the radiation storm diminishes. The greater
than 100 MeV flux levels are expected to remain above the 1 pfu
threshold for the first part of day one (13 Sep) with a chance of
exceeding that threshold again on day two (14 Sep).

C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Sep 13-Sep 15 2017

              Sep 13        Sep 14        Sep 15
R1-R2            1%            1%            1%
R3 or greater    1%            1%            1%

Rationale: No R1 (Minor) or greater radio blackouts are expected.  No
significant active region flare activity is forecast.


# Global Ionospheric Radio Observatory

# GIRO Tabulated Ionospheric Characteristics, Version 1.0 Revision B
# Generated by DIDBGetValues on 2017-09-13T02:44:48.898Z
# Location: GEO 64.66N 212.93E, URSI-Code EI764 EIELSON
# Instrument: Ionosonde, Model: DPS-4D
# Query for measurement intervals of time:
# 2017-09-13T02:00:00.000Z - 2017-09-13T02:30:00.000Z
# Data Selection:
# CS is Autoscaling Confidence Score (from 0 to 100, 999 if manual scaling, -1 if unknown)
# foF2 [MHz] - F2 layer critical frequency
#Time                     CS   foF2 QD
2017-09-13T02:30:00.000Z  70  4.625 //




Latest 24 Hour Ionogram Movies for Eielson AFB




Propagation Failure

Ionograms reveal no return signal reflections and recorded transmission were only of local ground wave stations


Hypothesized Conclusion

Failure of propagation due to Polar Cap Absorption manifesting as major D-Layer signal attenuation for central Alaska and other areas north of 60 degrees north latitude as shown in the image below. 




 Polar Cap Absorption

Being an artifact of  Proton event.


Latest World Ionogram