Aircraft Scatter

VHF/UHF WSPR
Aircraft Scatter

12 July 2012 - On http://planefinder.net N6GN noticed a FedEx flight, southbound on a path that took it about 8 miles east of Santa Rosa at about 13K feet. The plane took a turn to the east, starting about Petaluma on this path.

25. 12 July 2012 - On http://planefinder.net N6GN noticed a FedEx flight, southbound on a path that took it about 8 miles east of Santa Rosa at about 13K feet. The plane took a turn to the east, starting about Petaluma on this path.


12 July 2012 - At 0444 UTC, when the FedEx plane flew overhead, a trace from KI6STW shows such a strong aircraft scatter (ACS) component that it didn't decode. Furthermore, the reason for the lack of decode was that the ACS components were quite close to transmitted frequency for a significant portion of the 2 minutes, particularly at the start. Since this aircraft was flying almost exactly along the path between the two stations, the indirect path length wasn't changing much. As the turn progressed, the path started getting longer to both N6GN and KI6STW from the aircraft and the ACS (Doppler) component dropped in frequency.

26. 12 July 2012 - When the FedEx plane flew overhead at 0444 UTC, a trace from KI6STW shows such a strong aircraft scatter (ACS) component that it didn't decode. Furthermore, the reason for the lack of decode was that the ACS components were quite close to transmitted frequency for a significant portion of the 2 minutes, particularly at the start. Since this aircraft was flying almost exactly along the path between the two stations, the indirect path length wasn't changing much. As the turn progressed, the path started getting longer to both N6GN and KI6STW from the aircraft and the ACS (Doppler) component dropped in frequency.


2012 Perseid Meteor Shower

27. ‎12 Aug 2012 - 0725 - 1430 UTC - 144 MHz WSPR Study (Perseid Meteor Shower) A few very bright, long and steep descending Doppler echoes at 0726 and 0758 are probably aircraft scatter (ACS). The much shorter duration traces at 0916, 1052 and 1138 may be meteor echoes. The ACS echoes increase rapidly after 1250 due to local air traffic.



REFERENCES

  1. Aircraft Scatter (ACS), Larsson I, SM6FHZ
  2. WSPRnet.org
  3. Hepburn's Tropospheric Ducting Forecasts
  4. California Temperature Inversions, Iacobellis et al.
  5. 144 MHz Propagation Study across the Alps
  6. 144 MHz WSPR Operations in Australia

LINKS

  1. 2 Meter WSPR Discussion Group
  2. 144 MHz WSPR Study Photo Album
  3. 144 MHz WSPR Study Spot Database
  4. 144 MHz WSPR Study Videos - KP4MD
  5. 144 MHz WSPR Study Videos - KC6KGE
  6. 144 MHz WSPR Study Videos - N6GN
  7. 2m WSPR (Radio Stability (M1GEO)
  8. Australian 2m WSPR Group
  9. Idiot's Guide to 144 MHz WSPR (VK3BQ)
  10. WSPR Propagation Study Paths Map
  11. Google Earth KML File
  12. Current WSPRnet 144 MHz Spot Reports
  13. WSPR Spot Report Analysis Spreadsheet with Charts

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