It's possible, so when it happens again, you might be able to find the "shadow" and its bounce, by pinging all those SDRs' - you can then localize the pattern back to the source of the noise, if it's possible that we were hearing a skip / tropo - event originating from another location on the opposite side of the planet.
The "masking shadow" is the SDR's that don't see this noise, while the bounce ones are the SDR's that pick up this birdie.
The reason I brought up Star Link is due to the errant behavior that they tend to exhibit at times from directly overhead of the listener- the solar events that affect our planet from the suns solar cycle activity and coronal holes that bombard these satellites - they supposed to operate within a boundary range that keeps them low enough to stay away from those Van-Allen belts but with the Earths own magnetosphere weakening and acting funny - Van Allen and the upper atmosphere are now wreaking havoc with each other (currents) so anything is possible.
The "masking shadow" is the SDR's that don't see this noise, while the bounce ones are the SDR's that pick up this birdie.
The reason I brought up Star Link is due to the errant behavior that they tend to exhibit at times from directly overhead of the listener- the solar events that affect our planet from the suns solar cycle activity and coronal holes that bombard these satellites - they supposed to operate within a boundary range that keeps them low enough to stay away from those Van-Allen belts but with the Earths own magnetosphere weakening and acting funny - Van Allen and the upper atmosphere are now wreaking havoc with each other (currents) so anything is possible.