CODAR caused a great deal of interference on the USAF MARS HF nets I used to participate in. It's hard to imagine the amount of chaos a 40 watt signal can cause, but that swooshing sound made our voice nets almost unusable. It was a miserable hour trying to hear net control or pass traffic most evenings.
Thanks for the great info. Was picking up signals that looked like that yesterday in the San Antonio. Was working 20 meters and saw this signal just above the ham band range. This was captured using a SDRPlay RSP2 radio. Check out my blog on this SDR - spectrum listening activities and configurations at: www.srdradiolistening.home.blog. Thanks again and 73, Brian WH2ACT
This would seem to fit the CODAR signature, except there appears to be a dual signal with one traveling "backwards", unless it's just an artifact of my radio's refresh rate. KC8HQX