TLDR (conclusion from the paper):
"By a combination of these techniques the satellite Cosmos 2546 (NORAD ID 45608) was identified with high confidence as
one source of the interference. Further analysis pointed to the Russian Edinaya Kosmicheskaya Sistema, an early warning
constellation to which Cosmos 2546 belongs, as collectively responsible for the wide-area transient interference causing GNSS
degradation across Europe since 2019."
NKosmatos•10m ago