AIS targets from afrika ?

[mari-caribbean]

Hello, i dont know if this is a bug or not does anyone else have AIS targets that should not be visible ?
all targets appear to not be moving or be at 0.1kn
or is there a new type of AIS i'm unaware off ?
i looked some up on MARINE RADAR and they do appear in those locations.

Bastiaan

[StuM]

It's been discussed on several occasions; Atmospheric or Tropospheric ducting



https://en.wikipedia.org/wiki/Tropos...pheric_ducting

"Tropospheric ducting over water, particularly between California and Hawaii, Brazil and Africa, Australia and New Zealand, Australia and Indonesia, Strait of Florida, and Bahrain and Pakistan, has produced VHF/UHF reception ranging from 1000 to 3,000 miles (1,600 – 4,800 km)."

[mari-caribbean]

thank you, i did google causes and did search this forum but did not find anything
but im kinda land locked with mountains in the direction of the african targets
so was wondering if maybe they started with those satelite AIS units

B

[CarCode]

Have a look here to check the actual Tropospheric ducting:
https://www.dxinfocentre.com/tropo_eur.html#hour6

[mari-caribbean]

yes but its mild , and not 4500 nml but i guess i dont have an other explination