One-hop E region propagation

Title: Example of E region propagation via one-hop from WWV at 5 MHz

Contributed by: Gwyn Griffiths G3ZIL

Reviewed by:

Receiving Station Location: KD7EFG Northern Utah SDR site near Corrine, Utah DN31uo

Receiving Station Details WSPRDaemon Grape SDR receiver.

Feature Description

Regular, daily, ionoisation in the E region between 95 and 120 km height enables primarily daytime radio propagation. Height of reflection varies little through daylight hours and hence Doppler shift is low. There is no equivalent to the descent in height of reflection of some 200 km as seen for F region propagation at dawn. This record at 5 MHz on the 617 km path between WWV and KA7OEI, Northern Utah shows the flat, essentially zero Doppler shift characteristic of E region one-hop propagation. PyLap ray tracing confirmed E region propagation between 1500 and 2400 UTC when the signal here was strongest. However, in this record E region propagation seems to have started at ~1230 UTC.