I should have hit the 'record' button on the TV and then tried to photograph what I meant.
Hope we don't have the on-the-ground excitement very often, but it is weather.
I'll try to do some research, and Chief, if I can't get answers, perhaps see if it is Ok with your neighbor and friend if I formulate a question to send to her for consideration.
As far as the sweep, the antenna DOES rotate, and I know the wizards in the little chips do marvelous things digitally after the basic data are received. But as you say, it is more like an old version of a PIP display, although i do know by watching the 'sweep' across an area with a fast moving rain front there is a little change in position as the sweep indicator passes. Probably a combination of both.
In today's digital world, not much surprises me any more. In the days of analog and the tremendous attenuation by rain and other precip the further you go out, the more of a chance of having what looks like a clear spot become very congested once you try to fly into it and find out that it was just being hidden. Of course the aircraft radars have far smaller antennas and less power.
But think of ground clutter with evening temperature changes and try to filter that out with pure analog stuff.
I welcome more input from others and will let this thread know with an update if I can find anything more to share.
I have to leave with one of my favorite RADAR stories. The DEW line up in Alaska and i think shared with Canada was just online when a few incoming Russian planes were seen. Then a few minutes later, a lot more, and finally a whole slough of them.
Turns out the enormous antennas and megawatts of power were seeing the moon rise and the long delayed echo was falsing the displays. Nowadays pulse encoding and other tricks would null out spurious returns but it made a few people very nervous for a few minutes. A little astronomy lesson and things settled down.
And of course in early June, the LaCrosse, WI, radar picked up a huge storm, moving the wrong way in clear air. Yup, the annual buffet for fishes, also known as the Mayfly swarm was a particularly vibrant color change for a bit.
I'm sure there are others, but fun for surprises.
Dale