I used to work on a Naval surface to air missile system. This used a pair of pulse-doppler radars. Talking to the radar guys, I remember one of them saying that with Helicopters, they'd get high power returns indicating both low speed (fuselage) and high speed (rotor) emanating from the same area. Internally, the radar signal processor would reconfigure itself slightly to allow for the 'split personality' of the signal (and maybe the pilot !!)
As an aside, during tracking & firing trials, there was a camera atop the tracker mount. In the picture produced by this camera was a little white box indicating the strongest radar return, i.e. where the radar was actually 'looking'. It was interesting to watch this square jumping around on the target as it came towards us. It pretty much jumped from rivet to rivet.