On: EU's GPS satellites have been down for four days i...

[alecmg]

Some devices supposedly can fall back to Galileo (now also down, nobody noticed), russian GLONASS and chinese... BeiDou.

How could I test that?

[M2Ys4U → alecmg]

>Galileo (now also down, nobody noticed)

Galileo hasn't reached full operating capability yet, so that's probably why few people have noticed (as why would you depend on an incomplete system?)

[_pmf_ → alecmg]

If you have 60000 EUR+: https://www.rohde-schwarz.com/de/produkt/smbv100a-produkt-st...

Something similar is used to test German Toll Collect On-Board Units (OBUs) before refurbishment.