Input required from existing and prospective GPS/LPV approach users

I wonder who they are. The domain name is registered via Schlund and partners in Germany, it doesn’t look (to me) like something EASA or another "official"body are involved with. So who are the GSA?

OK, so another quick google shows that the GSA are a real organisation:

http://www.gsa.europa.eu/

But what is this sbas4aviation.eu

Smells fishy to me, but I don’t know why I think that!

And a ruse to get a database of potential avionics customers too?

Or maybe it’s absolutely genuine