Jay Honeck wrote:
They have a radar to refer to. They are not radar controllers.
Pretty much any class D near a larger class C or B airport will have
a scope in the cab. Get away from a larger radar facility and
there's no radar for that smaller airport to have in the first
place. And some airports bought their own radar and had it added to
the system. That's happened here in Montana.

An aside: Lake Lawn Lodge (in Wisconsin) actually had their own radar
on the roof of their FBO. It looked like a boat radar (and I never
saw it in operation -- by the time I started flying in there, they
were on their way out of business), and I don't know what they could
actually SEE with it -- but it's the only uncontrolled field I've ever
seen with radar!

It was probably weather radar. And it was probably a marine radar.