multi-waveform sounder

heard on 9970.0 KHz (cf), about 3.6 Khz badwidth. The sounder consists of a "train" of n different length bursts, each burst has different sweep-rate and ends with a 200 msec tone, last tone is 380 msec width.Unfortunatelly, I went into this transmission when the sounder was still on-air, so I had the time to observe only the last three bursts, below reported as burst n-2, burst n-1 and burst n

 

Below the analysis of the bursts, as precise as possible since my resources; as you may see, this is an FMCW system:

burst n-2

burst n-1

burst n

The scan session is characterized by descending sweep-rates (about: 16 -> 10 -> 4 sweeps/sec), I think it's oriented to test different propagations conditions at that same frequency but with different sweep-rates.

I hope to hear again this sounder so to write a better and complete analysis.