This radar signal I see is form the University of Twente's shortwave remote receiver. This radar signal has been going on for the day, starting at 14:00 (2:00 PM) and ending at around 20:00 (10:00 PM) It has a very monotone sound, and is a pretty strong signal. I haven't seen another Unidentified Signal page with it, unless i'm missing something. As for the waterfall, it has around 8 channels and looks like a smaller, more condensed version of the OTHR Pluto. Here's another picture of it, but from farther away. It's the signal that I have the yellow frequency scroller on.