Any fast sweep FMCW (Frequency Modulated Continuous Wave, swepted or chirped across the bandwidth during one continuous pulse or sweep) will sound like that. This technique is used by many HF Radars and HF Sounders. Some will stay at one rep rate and others will step rates and vary them, still others will combine these activities. In other words, yes, people are familiar with them, but it is almost impossible to get a valid, 100%, ID on the specific source location or specific system. It is, at times, possible to make a fairly educated guess as to the source.
The most common one I hear that changes rate starts fast and steps down in burst. Each burst contains 64 sweeps and the duration of the burst is however long it takes to do the 64 sweeps at that chirp rate. However, I have seen this same system stop stepping and go to a fixed rate for minutes at a time. Other systems sound like this but just remain at a fixed rate at all times.
Examples (both are strongly suspected of being from the JORN in Australia):
Notice the last burst in this example sounds rather like the recording you posted
Radar or Sounder, 8992 kHz, September 24, 2010, 1338 UTC - YouTube
Notice that this is similar to the previous example, but with a pilot tone before each burst
Radar or Sounder, 8992 kHz, April 17, 2011, 1510 UTC - YouTube
CODARs can be swept as fast as your example, but since they are an IFMCW (Interupted Frequency Modulated Continuous Wave, a long pulse with a relatively short pause between pulses, chirp during the pulse, multiple pulses per sweep) they have a bit more raspy sound, you can hear the pulse sound imposed on the swept RF.
T!
