Yeah, i guess you right. Probably a raining sky would defeat the photonic stuff.
Anyway, wonder how huge will be that reduction of detection range in the (near) future. IMO is cheaper build better sensors than stealth aircrafts.
Looks like the 35 (or others) is not that stealth after all..
Came across this article while browsing the site :
http://www.liveleak.com/view?i=02b_1395416459