I got nothing here all the way through the spectrum-I guess it couldn't break my bubble
HOWEVER....I do get these similar blips in the military HF ranges such as 4-5khz 18-19khz and one or two around 24-26khz. If you listen to mine they are at 1 sec intervals and they have a "shoop" characteristic-if you listen closely to Brandon's I mean REAL close-there seems to be the same thing only way more abrupt. I call it to be radar. But wada I know
I assume you mean 4-5 MHz, not kHz. Likewise the 18-19 and 24-26 range, MHz, not kHz.
The "shoop" sound you are describing is the frequency sweep of the radar. That is the important part that is missing from the sound clip Brandon posted, if you put it through spectrum analysis software, maybe like Spectrogram, you will see it is a simple pulse with no sweep.
As I said, a pulsed radar with a 1 second PRI and no sweep is going to be extremely limited in function, and a near complete waste of time and money. As far as I know there are no HF radar systems anywhere in the World that have a simple, unmodulated, pulse with a PRI that slow. There is NO advantage to such a system and a lot of wasted effort. Either shorter PRI's or FMCW or a combination of pulsed FMCW is the rule, other than that you are spending a lot of money and getting little return.
A simple pulse (this description does NOT apply to an FMCW or IFMCW swept radar pulse) with a PRI of 1 second would yield a maximum unambiguous range of just about 93,000 miles. But the longest path you can possibly have around the Earth is just under 25,000 miles, so you would be unable to tell where your return is actually coming from, is it on the first lap of Earth or did it skip over (and increase ambiguity) and not paint until the second? This indicates that there would never be a need for a PRI longer than about 0.27 seconds to get a return off of anything on the Earths surface or near atmosphere. Slower PRI's result in less average energy returned from any target, making it less likely to be detected, so a general rule in radar design is to always use the fastest PRI you can get away with that does not impact other design constraints. Also, you can not expect propagation to really yield round the World conditions most of the time, so you pick your freqs and PRI's appropriately. You would calculate the maximum usable range for a given frequency and use that to define the fastest PRI you can get away with, then NEVER exceed that number unless you want to reduce your detection range. You can slow down from that point, longer PRI's do have uses such as differing blind speeds, but doing so cost you returned energy from the target so you only slow down as little as you have to.
Your video example is something called CODAR, it is a specific type of short range ocean surface monitoring radar (and it is NOT military). CODAR has sweep rates that generally run from 5 per second to 0.66 per second, 1 to 2.5 per second is the most common range for CODAR.
Here is a list of CODARs I have received at my location, it is far from complete, these are just the ones I have bothered to measure parameters on.
http://token_radio.home.mchsi.com/CODARs_cf_10052009.HTM
T!