Unident Signal 10.152 MHZ- Any Idea?

[Cronus]

Greetings All,

Came across this at 14:45 UTC in the midwest, centered just above the 30 meter ham band.
Looks to be about 10khx wide, I have audio Recordings as well, if it would help. I was unable to locate it on the signal wiki page:

Here is the screenshot:

https://i.postimg.cc/KcrTXYDV/signal.png

[Token]

That is a radar.  Since it is FMCW, varying rep rate, and has what looks like a single pulse pilot tone or pre-beep it is quite possibly JORN out of Australia.  However, that is not certain.  The US ROTHR can operate with a single pulse pre-beep and look rather like this image, and there is also a Chinese radar that can use a very similar mode.

Most probably JORN, second guess US ROTHR, possibly Chinese.

The Signal Wiki page is a good starting point, but it is far from a complete reference, however, both JORN and US ROTHR should be there.

T!

[Cronus]

Thanks for the reply!
First time I had noticed it on that frequency... Good info you provided, and I will do a bit more reading on it as well.

[Token]

The thing to remember about the candidate radars, and most HF radars that change frequency at all, is that they have no set frequencies they use.  Most of them can move to any frequency they need, when they need it.  They often have frequency ranges they won't touch, but that is probably more of a black list kind of thing.  They often stay out of broadcast bands, away from aero freqs, and generally outside of ham bands (some radars, such as the Russian 29B6 and the Chinese OTHR-SW are notorious for hammering ham bands).

Changing frequency is part of how HF radars control what part of the earths surface they are watching.  They leverage current, and changing, propagation conditions to get the right skip path to the region they are interested in.  So they go to the frequency necessary when necessary, to get the job done.

T!