Odd occasional across spectrum signal

[Blueliner]

I am a real newbie to SDR but find it fascinating. I've noticed that on the waterfall of the SRDConnect and SDRUno, there is an occasional signal that tracks across the entire visible frequency spectrum on the waterfall. As it passes the tuned frequency, it gives a little "pip". It runs from low to high frequency, and takes about a second to span the viewed spectrum on the waterfall, leaving an inclined trace line across the entire waterfall.

I apologize if I'm not using the correct terminology to describe this but has anyone else noticed this? What or who generates it, and could it just be a local interference thing?

Thanks in advance for any thoughts or comments.

 

[Whiskey3JMC]

What band are we talking about here? A screenshot or video may help

 

[Blueliner]

I will try to get a screen shot of the waterfall on SDRConnect. May be a while before I can.

 

[dlwtrunked]

I am a real newbie to SDR but find it fascinating. I've noticed that on the waterfall of the SRDConnect and SDRUno, there is an occasional signal that tracks across the entire visible frequency spectrum on the waterfall. As it passes the tuned frequency, it gives a little "pip". It runs from low to high frequency, and takes about a second to span the viewed spectrum on the waterfall, leaving an inclined trace line across the entire waterfall.

I apologize if I'm not using the correct terminology to describe this but has anyone else noticed this? What or who generates it, and could it just be a local interference thing?

Thanks in advance for any thoughts or comments.

I assume yo mean HF range (2-30 MHz). If so, you are almost certainly talking about a radiosonde. These stations are used to study radio conditions. The most often ones heard in the U.S. are the ones at the U.S.N. ROTHR (Relocatable-Over-The-HorizonRadar) sites. (What you see is not the radar but used to tell the radar which frequencies are "good".) This information is also given to Homeland Security and the DEA. There are sites in:
ROTHR-VA New Kent transmit and Chesapeake receive
ROTHR-TX Premont transmit and Freer receive
ROTHR-PR Playa Grande (Vieques) transmit and Ft. Allen (Ponce) receive(There are other sites in the world but the above will be the strong ones in the U.S.)
•Both ionsondes start simultaneously every 12 minutes.
•The 2-20 MHz ionosonde sweeps upwards at 10 s/MHz.
•The 5-28 MHz ionosonde actually sweeps with 100 kHz segments having 20 kHz sub-segments with sweeps at 10 s/MHz (100 Hz/ms). The overall effect is 12.2 s/MHz except when due to exceptions (next bullet).
•The 5-28 MHz ionosonde skips over frequencies for WWV, search and rescue, and other frequencies. There are transmission delays at 7.900, 11.900, and 17.800 MHz.
Sometimes you will only see 1 of the two from a site. Due to the two at each site being different, the two at each site will "cross" *use the same frequency momentarily) around somewhere in the 17 or 18 MHz range--often a little below 18.1 MHz).
(Source: me adn my studies of such things)

 

[Blueliner]

OK, tuned to 19M band and I missed 2 passes trying to capture the screen shot, but this one I got. 11:33 hours on 19M band. I hope the image I posted below is visible.
As it passed the tuned frequency, it made a sort of "squeak". Total transit time is about 1 to 2 seconds. One more passed as I was working with the screen shot, it was a less strong signal. From memory, I don't think this is isolated to 19M but is where I found them just now.

Thinking back I had the same using SDRUno at my former home an hour and a half south of my current home so it may not be local to my location. Or, maybe something in the SDR software or SDR itself. ? Does weather radar make some kind of sweeping signal?

 

[Blueliner]

Sorry, I was posting and missed your great reply. Very helpful and seems to describe what this newbie is seeing.
Thanks!!
Oh, and Happy New Year!

 

[popnokick]

Yep - radiosonde / ionosode

 

[dlwtrunked]

Yep - radiosonde / ionosode

I assume yo mean HF range (2-30 MHz). If so, you are almost certainly talking about a radiosonde. These stations are used to study radio conditions. The most often ones heard in the U.S. are the ones at the U.S.N. ROTHR (Relocatable-Over-The-HorizonRadar) sites. (What you see is not the radar but used to tell the radar which frequencies are "good".) This information is also given to Homeland Security and the DEA. There are sites in:
ROTHR-VA New Kent transmit and Chesapeake receive
ROTHR-TX Premont transmit and Freer receive
ROTHR-PR Playa Grande (Vieques) transmit and Ft. Allen (Ponce) receive(There are other sites in the world but the above will be the strong ones in the U.S.)
•Both ionsondes start simultaneously every 12 minutes.
•The 2-20 MHz ionosonde sweeps upwards at 10 s/MHz.
•The 5-28 MHz ionosonde actually sweeps with 100 kHz segments having 20 kHz sub-segments with sweeps at 10 s/MHz (100 Hz/ms). The overall effect is 12.2 s/MHz except when due to exceptions (next bullet).
•The 5-28 MHz ionosonde skips over frequencies for WWV, search and rescue, and other frequencies. There are transmission delays at 7.900, 11.900, and 17.800 MHz.
Sometimes you will only see 1 of the two from a site. Due to the two at each site being different, the two at each site will "cross" *use the same frequency momentarily) around somewhere in the 17 or 18 MHz range--often a little below 18.1 MHz).
(Source: me adn my studies of such things)

I assume yo mean HF range (2-30 MHz). If so, you are almost certainly talking about a radiosonde. These stations are used to study radio conditions. The most often ones heard in the U.S. are the ones at the U.S.N. ROTHR (Relocatable-Over-The-HorizonRadar) sites. (What you see is not the radar but used to tell the radar which frequencies are "good".) This information is also given to Homeland Security and the DEA. There are sites in:
ROTHR-VA New Kent transmit and Chesapeake receive
ROTHR-TX Premont transmit and Freer receive
ROTHR-PR Playa Grande (Vieques) transmit and Ft. Allen (Ponce) receive(There are other sites in the world but the above will be the strong ones in the U.S.)
•Both ionsondes start simultaneously every 12 minutes.
•The 2-20 MHz ionosonde sweeps upwards at 10 s/MHz.
•The 5-28 MHz ionosonde actually sweeps with 100 kHz segments having 20 kHz sub-segments with sweeps at 10 s/MHz (100 Hz/ms). The overall effect is 12.2 s/MHz except when due to exceptions (next bullet).
•The 5-28 MHz ionosonde skips over frequencies for WWV, search and rescue, and other frequencies. There are transmission delays at 7.900, 11.900, and 17.800 MHz.
Sometimes you will only see 1 of the two from a site. Due to the two at each site being different, the two at each site will "cross" *use the same frequency momentarily) around somewhere in the 17 or 18 MHz range--often a little below 18.1 MHz).
(Source: me adn my studies of such things)

I will try to get a screen shot of the waterfall on SDRConnect. May be a while before I can.

I typed "radiosonde" in my first sentence when I meant "ionsonde" and got it right after that. ( I also chase weather balloons radiosondes and just posted something elsewhere about those and the word was still in my tired typing fingers.) Anyway, here is a photo of the New Kent, VA transmit site and a screen capture of one of the ionsondes skipping over the two frequencies being used by the ROTHR radar. (Note the other ionsonde at New Kent is different and looks "smoother".) a
And finally the 2 ionsondes crossing that I mentioned. If one join/go to groupsio UXDF files section, you can find my talk on these and some other HF radar types.

 

[dlwtrunked]

OK, tuned to 19M band and I missed 2 passes trying to capture the screen shot, but this one I got. 11:33 hours on 19M band. I hope the image I posted below is visible.
As it passed the tuned frequency, it made a sort of "squeak". Total transit time is about 1 to 2 seconds. One more passed as I was working with the screen shot, it was a less strong signal. From memory, I don't think this is isolated to 19M but is where I found them just now.

Thinking back I had the same using SDRUno at my former home an hour and a half south of my current home so it may not be local to my location. Or, maybe something in the SDR software or SDR itself. ? Does weather radar make some kind of sweeping signal?
View attachment 153935

Notice that you see the ionsonde also, paired with it at the same site in the upper left corner of the waterfall. As I mentioned, each of the 3 ROTHR has 2 different ones of different types. Also, weather radar does not use HF (shortwave) and operates above 2GHz (and does not look anything like this. (NWS NEXRAD weather radar uses 2.7-3.0 GHz and TDWR, Terminal Doppler Weather Radar) uses frequencies around 5.6 GHz.)

 

[Token]

Sorry, I was posting and missed your great reply. Very helpful and seems to describe what this newbie is seeing.
Thanks!!
Oh, and Happy New Year!

Others have provided the answer, but be aware there are dozens of these kinds of sounders around the world. This kind of ionosonde is also called a "chirpsounder". I have seen them active from 2 MHz to over 34 MHz. The two most popular chirp rates I have observed are 100 kHz / second and 150 kHz / second.

They have been around for decades. However, before waterfalls were popular most listeners did not realize what that "pip" (or tweep sound in SSB) meant.

T!