Recognize this SCADA signal?

[N9JIG]

Many mornings in my neighborhood I hear the below signal on 461.100 so strong that it trips my CloseCall scanner and I can hear it with no antenna on a portable around my neighborhood. It usually lasts a few hours and is usually gone sometime after lunch.

I assume that it is probably from our local electric utility (APS) but have not been able to pinpoint its location. There is a high-tension line a couple blocks away as well as a substation nearby. It is NOT coming from that substation as I cannot hear it with no antenna from there.

I went around the neighborhood and suspect it might be coming from some remote switch or something but it might be on the golf course and not accessible without a set of clubs.

Does anyone recognize they signal type and can confirm it is likely electric utility based? I wonder if it might be interrogating data from smart meters or solar systems.

Dropbox

www.dropbox.com

 

[mtindor]

Many mornings in my neighborhood I hear the below signal on 461.100 so strong that it trips my CloseCall scanner and I can hear it with no antenna on a portable around my neighborhood. It usually lasts a few hours and is usually gone sometime after lunch.

I assume that it is probably from our local electric utility (APS) but have not been able to pinpoint its location. There is a high-tension line a couple blocks away as well as a substation nearby. It is NOT coming from that substation as I cannot hear it with no antenna from there.

I went around the neighborhood and suspect it might be coming from some remote switch or something but it might be on the golf course and not accessible without a set of clubs.

Does anyone recognize they signal type and can confirm it is likely electric utility based? I wonder if it might be interrogating data from smart meters or solar systems.

Dropbox

www.dropbox.com

Might be WQAW399 Maricopa Co DOT
"Applicant is engaged in providing water services to the general public. Radios will be used to coordinate GPS/RTK operations."

 

[nd5y]

If it repeats at 1 second intervals like that it's probably GPS/RTK.

 

[IC-R20]

Yes I remember that sound well. It is RTK, my local county Parks Department building had one that could be heard all over town. I was able to set my Trimble handheld to the same frequency and get sub 1 foot accuracy with it, was really helpful for mapping OpenStreetMaps back then since my area still had a lot of garbage data from when they imported those census bureau TIGER maps to fill in the USA so I had to fix almost everything.

 

[N9JIG]

So would GPS/RTX be used for surveying (if that is what this is)?

I am trying to find the actual source as it is very close to my house but I haven't been able to pinpoint it. It comes and goes, and when it is on it is usually weekday mornings for a few hours.

 

[nd5y]

Surveying, construction, farming, probably other uses.
I haven't heard if it is need for stuff like self-driving vehicles/robots/drones.

 

[mtindor]

Surveying, construction, farming, probably other uses.
I haven't heard if it is need for stuff like self-driving vehicles/robots/drones.

Yep autonomous vehicles as well.

 

[bearcatrp]

Any black vans driving around?

 

[N9JIG]

Any black vans driving around?

No but a real uptick in black helicopters!

The fact that it is sporadic leads me to lean toward construction. There are several sections around my development that are under construction with new streets and homes going in so the next time it pops up I will look for surveyors in the field working.

 

[IC-R20]

So would GPS/RTX be used for surveying (if that is what this is)?

I am trying to find the actual source as it is very close to my house but I haven't been able to pinpoint it. It comes and goes, and when it is on it is usually weekday mornings for a few hours.

Yeah probably a survey crew using a portable unit. My handheld also came with it’s own RTK transmitter unit though I haven’t really used it much. But what you do is set it over a set of very precisely known coordinates commonly over a survey disc marker and it compares that to the GNSS signal from its own receiver and then transmits the correction info over that RF signal you head to the handheld for centimeter accuracy. So long as you position the RTK right, otherwise it’s fake confidence.

 

[IC-R20]

 

[sflmonitor]

I had a close call hit on 461.1 not too long ago while driving past a road construction site. I pinned the transmitter location and it was indeed GPS surveying equipment. Sounds a lot like yours, just a tiny bit slower.

 

[N9JIG]

So is this GPS-RTK signal just a basic beacon signal or does it have unique data? If there is some sort of data is it readable with some software?

(Edited a few minutes later):

I have it isolated to a construction yard 2600 feet away from my house but it is really strong so I assume it is putting out more than a 4 or 5 watt signal.

The radome is located to the right of the land mobile antenna. BTW, I don't know what the vertical antenna is for as I have not heard them using any radios other than the odd FRS here and there for crane lifts and other coordination. I wonder if it could be for wireless internet to the construction office...

 

[sflmonitor]

So is this GPS-RTK signal just a basic beacon signal or does it have unique data? If there is some sort of data is it readable with some software?

I think I have it isolated to a construction yard a couple blocks away but it is really strong so I assume it is putting out more than a 4 or 5 watt signal.

From how it’s been explained to me, the outgoing RTK base data stream is some form of GPS correction message. The bulldozer’s GPS receiver reads its own satellite signals and receives the base’s corrections simultaneously. The corrected coordinates are fed into the bulldozer’s computer, which adjusts the necessary parameters.

I read somewhere that Trimble’s RTK transmitters can be set up to transmit between 0.5 - 2 watts on UHF. I was able to hear the system near me for almost 1 mile out. I was using a Uniden 436 with a mobile antenna.

Here in Florida, the state DOT has a network that is supposed to enhance and/or integrate with these systems. https://www.fdot.gov/Geospatial/fprn.shtm

 

[N9JIG]

From how it’s been explained to me, the outgoing RTK base data stream is some form of GPS correction message. The bulldozer’s GPS receiver reads its own satellite signals and receives the base’s corrections simultaneously. The corrected coordinates are fed into the bulldozer’s computer, which adjusts the necessary parameters.

I read somewhere that Trimble’s RTK transmitters can be set up to transmit between 0.5 - 2 watts on UHF.

Here in Florida, the state DOT has a network that is supposed to enhance and/or integrate with these systems. https://www.fdot.gov/Geospatial/fprn.shtm

Here is Arizona I found a similar map at Home. This site however is not listed, the closest one is 20 miles to my east or another at 21 miles due south. I assume that the one I am hearing is not part of the grid as it will go away when the construction in my area has been completed.

 

[sflmonitor]

Here is Arizona I found a similar map at Home. This site however is not listed, the closest one is 20 miles to my east or another at 21 miles due south. I assume that the one I am hearing is not part of the grid as it will go away when the construction in my area has been completed.

Correct, I believe it’s the same with the one that I heard near me. They are temp sites that feed off the permanent ones for accuracy.

 

[16b]

I would guess that vertical antenna in the photo is for the UHF transmitter you are hearing (with the small radome next to it being the GPS antenna). I imagine a couple of watts into that thing would make it easy to hear a half mile away unless there are a lot of obstructions.

These systems are popular with farms in my area. The transmitter is often located on top of a grain silo. They are usually run-of-the-mill omnidirectional UHF LMR antennas.

 

[IC-R20]

The dome receives the GNSS signals and the vertical beams out the RTK. If they’re using a base station it can easily put out the full 40-50 watts if they want to.