Daily unidentified digital signal on 7200 kHz (03:00–03:27 UTC) – Any ideas?

[Steph]

Hello everyone,

I've been observing an unidentified HF digital transmission on 7200 kHz for several days from Quebec, Canada.

Here are the characteristics:

Frequency: 7200 kHz
Schedule: Starts every day at exactly 03:00 UTC (23:00 local EDT)
End: Stops abruptly at 03:27 UTC
Duration: Exactly 27 minutes
Bandwidth: Approximately 10 kHz
Appearance: A wide, "grainy" digital-looking signal with no obvious carrier. It looks like a continuous digital noise floor rather than a narrow PSK signal.
Behavior: The signal appears instantly at 03:00 UTC and disappears just as abruptly at 03:27 UTC. I have not noticed any obvious ALE sequence before it starts.

At first I thought it might be STANAG 4285, but the occupied bandwidth seems much wider than expected, so I'm now wondering if it could instead be MIL-STD-188-110, STANAG 4539, another wideband HF modem, or something completely different.

I'll attach a waterfall screenshot of the signal below.

Has anyone else observed this transmission, or can identify the waveform or the likely network using this schedule?

Any insight would be greatly appreciated.

Thanks!

[autovon]

I logged a DRM shortwave station the other day, same frequency and timeframe.  See if that might be it next time. 
https://www.hfunderground.com/board/index.php/topic,166143.0.html

ETA: TDF DRM French programming 0300z 18 July