[Windflier]

I would call it both amplitude and frequency modulated.

What inference do you draw from that?

[TXnMA]

I agree with Steely Tom's assessment in #39.

There are several (natural) ways to get a short pulse (amplitude modulation) from a rapidly spinning source.

Had the frequency sweep modulation been linear, then I might suspect an other-than-natural source. But -- the freq sweep is nonlinear...