QuadRF can spot drones and see WiFi through my wall
151 points - today at 3:59 PM
Sourcepiinbinary
today at 5:46 PM
One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from.
This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)
Not sure if you've heard of them, but they're starting to come to market with this exact thing aside from distance detection and more on the "which part is squeaking" side.
https://www.youtube.com/watch?v=l8-5lSVCR2w
mlfreeman
today at 5:01 PM
The visualizer reminds me of my thermal camera.
I have heard claims of devices (mostly TVs) supposedly coming with secret 5G cell uplinks built in [never heard a specific model mentioned though].
If there were more variants covering more commonly-used RF bands, people could walk around and literally check for once.
(incidentally i'm sure three letter agencies have had this sort of tech in their bug-detecting toolkit for a LONG time)
mikeweiss
today at 5:22 PM
Whos paying the telcos for those 5G connections and also has the FCC been degraded so much that they would allow for undeclared radios in consumer products?
The FCC is literally powerless nowadays for all intents and purposes. They've abrogated so much of their authority to the states now that they might as well be eliminated. What little authority that remains with it is bought and paid for to the point that I'm sure you could get anything "approved" if you wanted.
FuriouslyAdrift
today at 5:32 PM
More likely 4G LTE MTM (https://www.verizon.com/business/products/internet-of-things...). It's dirt cheap and paid for by the vendor of the device it is in (usually) in the name of 'telemetry'.
I've seen so many random industrial devices and parts come into our plant that have their own cellular it's wild.
throwaway85825
today at 5:25 PM
Secret 5G is not as common because there is a huge incentive to resell the free service. Maybe with eSIM it will be harder. Kindles uses to have a free data plan SIM.
I recall reading the original research paper from a student who made the same RF ‘camera’ here in hacker news.
Scene_Cast2
today at 4:13 PM
I wonder if this tool can help with EMC compliance testing. My TinySA needs an LNA, so I wonder if this has the required noise floor.
raziel2701
today at 4:54 PM
I don't see any professionals turning to this for EMC/EMI testing, they already have all the test equipment for that job.
varispeed
today at 5:12 PM
How about "non-professionals"? It could be useful to check device before sending for pre-compliance / compliance checks and save money - that would avoid very expensive iterations.
But there are already benchtop or handheld signal analyzer for that purpose.
This seems more like a tool for checking across entire large assemblies like an entire building, car, aircraft, etc, for unknown sources. If you have an individual discrete device that you're already testing, just using traditional instrumentation seems reasonable, but on a large, complex assembly, I can see it being useful. Also useful for things like detecting if a particular antenna is working without actually going up there to measure near it; if you have a MIMO setup with multiple antennas, this might make it easier to check if all of them are working correctly when mounted in inconvenient areas.
peteforde
today at 5:12 PM
That's absolutely missing the point. EMC/EMI testing is expensive, time consuming and requires scheduling and experiment design.
Being able to do local soft-run testing on-site to be sure that you eliminate the easy 90% of issues before you get to the lab would be a huge win.
I think that for a single device, this probably wouldn't help much over just having a more traditional signal analyzer, either benchtop or handheld. If you know what you're testing, just using a signal analyzer around it will give you a good first pass picture of emissions, and probably be much more informative and precise than this.
This seems more useful for finding unknown or hidden RF sources, for instance looking thorugh an entire building to find unknown RF sources, or maybe a whole complex assembly like a car or aircraft.
Historically these have been quickly shut down without much of an explanation.
Please elaborate.
There are literary step-by-step videos on how to build these.
E.g. https://www.youtube.com/watch?v=g3LT_b6K0Mc
Phased array radars are export controlled in the US. It doesnt mean its illegal to build or own, but it might be illegal to sell in some cases
I thought I remembered even seeing public Git repos with passive radar code that ended up getting shut down due to export controls?
Yeah, Kraken SDR removed some functionality due to these concerns, if I remember correctly.
Odd, because export controls don't generally apply to published material (like open source software), but maybe they were worried that because they were also selling the hardware they could have issues due to the combo being export controlled.
dzhiurgis
today at 6:04 PM
Wonder which LLM would be happy to vibe code it back (not sure if it would be able to pull it off tho).
illliillll
today at 4:50 PM
Do share some more details please
The explanation may be spelled ITAR.
fiatpandas
today at 4:23 PM
The visualizer app reminds me of the same UI / output you get from acoustic cameras.
Neat! SDRs have been available at reasonable price points for some time but the processing power to engage with wifi and other digital signals has been somewhat elusive. Assuming RAM can be purchased in the future, I think we might see a lot more prosumer-targeted devices for doing raw signal analysis in the future.
miranaproarrow
today at 5:06 PM
Do you have specific SDR in mind? I thought the v2 dongle doesnt have the range of Wifi? SDR is something Ive just recently want to learn to help me understand electromagnetism
It should be more specific, it spots RC drones operated on ~5.8ghz, it won’t spot RC on 900mhz, nor cellular enabled ones.
It also appears to have a fairly narrow detection angle. This might work for spotting a drone when you already know roughly where it is, but that problem becomes infinitely harder when you have to scan the entire sky.
RF drone detection has been a challenging problem for quite a while. Lots of solid state radar/RF detection products have emerged in the space, but it is not a trivial problem. And that is for drones with active RF comms, anything flying autonomously is even harder to detect at a far enough range to actually do something about.
> RF drone detection has been a challenging problem for quite a while.
Correct, there is no bullet proof cuas system to this date.
> anything flying autonomously is even harder to detect
Not just autonomously, because even in autonomous mode you would still need other RF like gnss, but you can fly drones without any rf signature at all and utilize a pre captured images saved on board to navigate the drone accurately using its cameras (normal or thermal). In this case, rf interference won’t work, it won’t be detected based on rf signature either, you will have to rely solely on visuals and acoustic, fly at night, and only left with acoustics.. it is a very hard task from technical standpoint.
Is that a limitation of the antenna? I though QuadRF uses SDR so can see many frequencies, not just the wifi things like ESPARGOS [0]
From documentation, QuadRF: Operating frequency range of 4.9 - 6.0 GHz (C-Band).
0. https://espargos.net/
Not the antenna, unfortunately, it only operates on the range of 4.9-6ghz.
It would be great to have a wider range like other SDRs but of course the cost will increase exponentially.
https://www.crowdsupply.com/scale-rf/quadrf
for lack of directonality?
for lack of frequency tuning
peteforde
today at 5:16 PM
I was almost through the checkout flow last week before I realized that this configuration only supports a relatively narrow frequency range.
I work primarily in sub-GHz radio. Please wake me up when they launch their LoRa version, that would be an instant purchase for me.
Sigh, fine. I will buy another radio gadget on crowdsupply.
The original quote for a single tile was $50-$100
They came out at $500
Being off by a bit is fine. Being off by 5x to 10x is.. Yikes.
Prices have gone a little insane in the last year though too to be fair to them.
Catloafdev
today at 4:46 PM
It looks like it has 4 tiles on it, no?
Yea its mimo 2x2.
Point still stands that they initially said it would be $50-$100. And its going for $500.
I mean if a single tile is 50-100, then 4 is 200-400, so it's not that far?
if it can spot/track drones that is a marketing opportunity for airports around the world that have to deal with drone nonsense which shut down flights for days
Most major airports will already have a counter-UAS system, it's a huge industry.
One big issue with radar is that it has the same problem pilots and human observers do: it struggles to distinguish drones from anything else in the sky (birds, balloons, planes, etc.). This is an active and improving research space, but by and large with radar, when your pilots report a drone, you still don't know how to figure out if it's the typical mis-identification or something real.
I'm reading about pilots spotting drones during takeoff/landing that the airport didn't know about
And I've read about airport shutdowns in UK and US without a single arrest which is why it keeps happening
So whatever system exists, apparently not good enough
Yes, primary radar has been useful for detecting airspace incursions since 1939. Nothing new here.
The difference with this kind of tech, though, is tracking down the operator.
pixelesque
today at 4:26 PM
If would likely need to track them well (not sure from this article/video if that's the case?) to be useful in that scenario...
Drawing a splodge in roughly the location (not sure if there's range info either? I doubt it if it's passive) overlaid on the video likely won't cut it...
ThrowawayR2
today at 4:51 PM
Phased array antennas (in use since the 1960s) and AESA (in use since the 1990s) are very mature tech that RF engineers are well aware of.
This gizmo is primarily interesting that it's pre-packaged at a price that hobbyists can afford.
btbuildem
today at 5:00 PM
Only the ones that use radio for control. The fiberoptic ones are "dark" to this setup.
There are more way advanced systems for cuas, where they infuse radar and visual and acoustic plus now AI to minimize the false positives, but practically speaking, they are not bullet proof and still fail. RID (remote ID) is a way to have a cooperative communication and was mandated in US, but there are ways too to spoof it and cloak it.
AndrewKemendo
today at 4:38 PM
> If the open source community can come up with something like this, just imagine what governments are capable of.
Since ~2022 and accelerated by the Russian aggression against Ukraine, governments are now behind both private and open source for frontier technology.
The companies that captured government contracts in the last century can’t move fast enough to bring tech into the government and national technology policy and funding is collapsing compared to the private sector
That’s new in history
vatsachak
today at 4:45 PM
Open source is the future. If everyone can work on it, we get better results for cheaper.
Open source doesn't mean the end of competition, since we are a competitive species.
I think the future economy is going to be some sort of UBI + large open source projects
onetokeoverthe
today at 5:59 PM
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