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
below S-scale storm level thresholds.

Solar Radiation Storm Forecast for Sep 16-Sep 18 2017

              Sep 16  Sep 17  Sep 18
S1 or greater    1%      1%      1%

Rationale: No S1 (Minor) or greater solar radiation storms are expected.
No significant active region activity favorable for radiation storm
production 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 Gakona 




Propagation Failure

Ionograms reveal a trace of F2 reflection followed by two more soundings without return signal reflections with an audio recording where during the time period 0200-021UTC net control AL7LX 316 miles south was heard however her signal vanished as propagation failed as indicated in graphs 0215-0230 UTC indicate.


Hypothesized Reason

Failure of propagation after 0215 UTC was apparently due to Polar Cap Absorption PCA, though not displayed in the below image, the 1db absorption display indicated a 10 db absorption level for 75 meters.



 Polar Cap Absorption



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