When I started out in QRSS weak signal modes in around 2004 sending FSKCW and such simple things... we quite often would notice doppler shifts, particularly around sunrise/sunset, due to ionsopheric?layer rapid movement. It could be a Hz or two and easily noticeable. You could also get reflections from nearby aircraft, with their own larger shift and quite distinctive.?
Both ends of the communication path can be fixed. But if the reflective thing(s) in the middle move then you can still get measurable doppler.?
On Mon, Sep 4, 2023 at 11:40?AM John Kirby <n3aaz_qrp_1@...> wrote:
More on Ionosphere Doppler between two fixed points
Yes Doppler-effect a fascinating subject
Seems like I've always know about the different between day/night propergation AND flutter (rapid QSB) but ...
...While tooling up for 2023 and 2024 solar eclips I discover there are four? 'Twlight Zones'? (Astronomical, Nautical, Civil? (first light), then SunRise) over each station for a total of eight that a common NE602 DC receiver and fldigi can detect and record (milli Hz) and amplitude (dB Volt) then plotted with EXCEL (see my page for more info)
Yet another facet on this marvoules ham radio hobby
