[Milsurplus] EMP and nukes in space

[CL in NC]

If you have 16 minutes, this is an interesting video.  There is a 1 minute or so ad for a video game near the beginning, but it does continue on.
Does anyone in this group have an idea of the theory behind the spinning yagis about 11 minutes in?  Early circular polarization, or measuring vertical/horizontal polarization wave fronts?

https://www.youtube.com/watch?v=EgCZFumiIec

Charlie, W4MEC in NC