We didn't give Jeff great direction on camera alignment calibration or setting the radio gain but he seemed to mostly figure it out. We're improving the UI based on his suggestions (it's open source so you can customize it too)
The RF augmented reality is just one of many applications of this brand new 4x4 MIMO software-defined radio built from the ground up. The AR uses a web app to stream RF points that your phone/laptop browser then live-merges with your local camera in the browser. I've been obsessed with low latency and high frame rate to make it a truly AR experience. More technical details at https://QuadRF.com/
The really intriguing part is the "Custom ADC" here, seems like some kind of 1-bit ΣΔ oversampling ADC (704 MSPS?). Single differential transistor, and captured by FPGAs LVDS RX.
Neat way to reduce cost and pin-count? But I think the typical FPGA clock tree has poor jitter performance. Not using the internal PLL(s) might help with spurs but the clock buffers are unavoidable.
The documentation mentions it's likely further degraded by noise from switching regulators. Oh the joys of hunting RF noise sources.
We've got the switching noise nailed down. Fortunately the LVDS jitter doesn't affect the sigma delta too badly because that impacts proportional to baseband frequency which is largely filtered out by the decimation filters beyond 40 MHz.. With a total of eight ADCs per QuadRF, you can see we are getting huge savings by being custom! While the per-ADC ENOB is 7-8 bits, another nice thing about phased arrays is that the quantization/ADC noise averages between elements, so with 8 ADCs in QuadRF we pick up another 1.5 bit giving 8.5-9.5 ENOB, which is frankly better than most SDRs. For the bigger phased arrays that improves further quickly.
Yeah, jitter doesn't matter too much at low frequency IF. I/Q calibration is more likely to be the bottleneck. That and close-in spurs from the fractional PLLs.
I have very little experience with MIMO / phased-arrays, this application likely doesn't need ultra high SFDR.
Yes, I actually designed the I/Q calibration for many of Analog Device's transceivers (AD93x), and indeed it is a fun problem. If you're interested in what was done for QuadRF, you can read: https://QuadRF.com/cals/txqec.html
(Warning: Math!)
Oh wow, the AD936x series was impressive for its I/Q calibration. Still is I guess, because there's been no compelling alternative even a decade later.
As I mostly deal with single channel applications, I get to use double superhet and avoid runtime calibration. Not an option here, Zero-IF has too much in the Pros column for multichannel.
I like to think of myself as pretty well-versed when it comes to hardware and software and even some RF. But this conversation has me hitting search a lot, lol. It's fascinating reading experts talk about a domain I have less experience in.
Super cool project I've been following for a while. Are you pivoting away from Earth-Moon-Earth radio astronomy? I first bookmarked this project when your site was hosted at https://open.space
Yes open-space was short-lived: https://domainnamewire.com/2026/04/08/u-s-defense-contractor... (good story though) We finally settled on Scale RF for the company and Quad RF for the product (and Moon RF for the bigger phased arrays!). Yes that incident kind of made our brand a mess..
Super cool! I noticed you had a blurb about it being used for mesh networks? Could you please go into more details/provide links to resources to learn more about that?
Absolutely :) we're working on documenting an awesome Meshtastic demo. Should have a writeup next week to add to the Crowd Supply updates page. Also Roy on our team will be demoing it (along with the RF augmented reality) at Teardown 2026 in Portland if you're in that neck of the woods.
We should have a video about MoonRF once we finish the QuadRF mass production, look for it ~ early September! Will be legendary! You can read on how the multi-tile synchronization and calibration works here: https://QuadRF.com/docs/#phased-arrays
It really depends on the transmitter strength, but if you set the Rx gain high on the QuadRF, we get within 2dB of the thermal noise detection limit.. so about as good as is possible with a receiver this size. I believe a few km is easily doable with a consumer drone but we haven't focused on it.
Funny, in the "imagine what governments are capable of" vein, I just read this[0] a few minutes ago before coming over to HN to find this post trending.
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?)
There are a few knockoff options too, which are not quite as nicely calibrated, but get the job done for much less than Fluke-level prices. Like the FOTRIC TD2.
These are the kinds of things you look at and think - maybe I DO need night-vision, or a soldering iron with a cpu, or a thermal imager, or a steerable endoscope or now an acoustic imager....
Has anyone tried acoustic imaging for water leaks inside walls? I live in a multi-floor 1900s Victorian. A leak can affect several units, and tracing the source can mean opening walls or floors in multiple places, and coordinating access has been getting harder with less WFH.
Could one of these tools help map water pipe routes and trace a leak, or are they only going to be useful for air and gas leaks?
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.
The army has one of these for sniper triangulation, and Boeing made a civilian version for optimizing sound dampening on the 787. I don’t know if they kept doing that on subsequent planes but I would expect so given how enthusiastic they were about being able to apply the weight budget to greater effect.
You need really high clock rate sensing to differentiate the arrival time for sound from microphone arrays where they are all less than a nanosecond separated from each other.
A nanosecond? The speed of sound at sea level in dry air is approximately 330m/s. So at say 3.3 kHz, the rough logarithmic middle of the audible spectrum, K=2π/lambda is 2π/0.1 m=20 π rad/m. A phase difference from a source difference k. ∆r would therefore likely be far more easily resolved than that for many physical ∆rs then, no?
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?
But in your scenario they are an integral and necessary part of the device, so it's costed in.
In a television it's an added cost and it's unclear if serving ads really can offset that extra $25-100 of hardware (and included data) you ship on a $200-1000 television.
It's also unclear to me if the low data packages they come with would be enough to serve meaningful ads to begin with. Those devices usually come with a fixed plan of 100MB/month for 5yrs (or along those lines). Modern smart tv ads are very often video or at least hi res images.
> In a television it's an added cost and it's unclear if serving ads really can offset that extra $25-100 of hardware (and included data) you ship on a $200-1000 television.
Amazon seems to have done the math and found that it makes sense to give a $20 discount on a $180 device if it lets them display very unobtrusive ads on the lockscreen. So I don't think you are correct.
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.
Not all mobile data APNs go to the Internet. You can't resell an IP service that lands on an RFC1918 network with exactly one IP:port available; the API endpoint.
Not saying I've seen this in devices, but I have built and run mobile data networks with private APNs.
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.
> has the FCC been degraded so much that they would allow for undeclared radios in consumer products?
Well... most TVs already have a WiFi/BT chipset for stuff like advertisements or, especially with Apple, high-bandwidth video streaming. There is already a radio module present, but (IIRC) you don't have to disclose what exactly that module is capable of.
I just kinda skimmed through it, so it detects drones in sky? Am I understanding this correctly? That might have some defense application considering what's going on in Eastern Europe right now.
It detects drones which send out RF signals at the same frequency band. Most drones used in Ukraine are tethered with thin optical wire exactly because one of the first anti-drone measures was to simply jam them at the frequencies the operators used.
There are some more advanced anti-drone measures at work: Like blasting them with directed high-energy microwaves to destroy the circuits.
Brute force wide band jamming would be easy too and would make hopping ineffective. Unless drones use self tuning antennas to overcome losses, they can't hop too far away from the antenna resonance frequency, which makes jammers job easier.
How come? It plainly negates the "easy" part. It's not easy at all, you need to scale your signal path to the magnitude of power. I.e. the expensive part.
FPV drones in the Russian war are generally pretty dumb devices, there's usually no frequency hopping involved to begin with. They have a lot more in common with baby monitors than with modern military comms.
Most drones aren't optical because optical drones sacrifice payload and distance, they're only used when broad spectrum jamming is expected. Jamming of that type is expensive and heavy enough that infantry probably won't be jamming, or light vehicles, or a lot of infrastructure.
> That might have some defense application considering what's going on in Eastern Europe right now.
This is a bog-standard phased-array RDF calibrated for WiFi freqs; that stuff is already in every single defense show.
Also, that's why there's jamming everywhere (to blind that kind of things) and why many UAVs are now tethered to optical fibers instead of being RF-controlled.
Really depends; there you can see both Lockmart exhibiting multi-billions project, and 150m after some Serbian company selling jet engines for UAVs for a couple hundreds.
I had a friend who'd just gotten out of EE school as a non-traditional student who was working for a company that was making radars for tracking drones maybe five years before the 2022 Russian invasion.
That was an active system, similar in concept to the radars used in air defense system just scaled down and faster acting.
The one in this article is a passive system that sees the transmitter on the drone. The comm link is the obvious weak spot on the drone as it can be detected and jammed, it is fairly inevitable that lethal attack drones that work anonymously will be widespread as a result.
According to CivDiv's channel about 70% of the drones used are still RC FPV drones. They are cheaper longer range and have a slightly simpler supply chain. Fiber optic cable prices have exploded because of the war.
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.
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.
I don't think it's any good for that. It's relatively narrowband and not the frequency you usually have issues with EMC on (5 to 6GHz - unless you are specially transmitting on this frequency you are unlikely to emit anything there).
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.
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
This has me thinking that fiber optic drones using this technology might be able to discover the location of signal-jamming equipment. But only for the good guys.
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.
As someone who works daily with export-control-adjacent hardware and software, my experience is that people tend to aggressively self-censor to a far higher standard than export control regulations actually require. The perceived headache of drawing the ire of whoever it is the enforces this stuff (which as I type this comment I'm just realizing I don't know who specifically is responsible for that) is so scary that people don't want to take any risk at all of being targeted.
> Direction finding equipment for determining bearings to specific electromagnetic sources or terrain characteristics specially designed for defense articles in paragraph (a)(1) of USML Category IV or paragraphs (a)(5), (a)(6), or (a)
ITAR part 121.
The "specifically designed for defense" probably makes this OK, but IANAL.
The covered materials are very broad, though often limited to equipment built "for purposes of", like in this section.
Title 22 Chapter I Subchapter M Part 121 - The United States Munitions List - Category XI Paragraph b
Electronic systems, equipment or software, not elsewhere enumerated in this subchapter, specially designed for intelligence purposes that collect, survey, monitor, or exploit, or analyze and produce information from, the electromagnetic spectrum (regardless of transmission medium), or for counteracting such activities.
At what point does a microphone become an intelligence device, when we have so many types of microphones. Is it an arbitrary label I can add or remove to a product? Will it apply equally to large manufacturers?
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.
> It sounds like they had to reverse-engineer the MIPI protocol used on the Pi 5 to do this (since it goes through the RP1 chip), and the way it's architected, you can daisy-chain multiple QuadRF modules together, letting each module calculate it's own phase shift.
How are they planning on distributing a shared, highly precise clock for that purpose? That's already a PITA if you do QO-100 modes that need high precision, but usually there it's enough to have one good clock that you feed to the LNA... but here? Every single one of these modules needs a very precisely identical timing signal and the kind of chips you can use to multiplex a reference clock signal are pretty expensive.
So, essentially, the secret sauce is tracing a known calibration source's movement to compensate for different cable lengths or weird physical tile arrangements? Neat!
Passive radar is fine for gigantic airliners with all regard for efficiency, none for radar cross section, and that fly above most obstacles. For drones you might be trying to scratch signal not only from below noise floor, but at the edges of quantization.
I thought that might just be Amazon resellers capitalizing on marks being too lazy to go off site at first when they were $280 at Microcenter (still crazy expensive). [0] Then Adafruit had them for the same $350! [1] And it really does seem to be driven by the ram too the 4 GB model is only $130 (or $104 at MC).
Just like eBay, an Amazon listing for a certain price does not mean the item is actually /selling/ for that price -- especially with badly-coded dynamic re-pricing algorithms hooked into listings these days.
With the end of easily available rtl-sdr dongles it's a relief to see someone has wrung such exceptional RF instantaneous bandwidth out of an RPI alternative interface. I really hope use of the camera interface for RF takes off.
> 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
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.
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...
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.
Yeah RemoteID is trivial to spoof using an ESP32. Most hobby pilots I know simply don't comply with RemoteID. And bad actors certainly won't purchase a $75 device to add to their drone.
It does become a bit more difficult with consumer grade off the shelf drones because it's built in. Still defeatable by the determined of course.
We have a quick demo video as well: https://m.youtube.com/watch?v=QvniJk3uNyA
Along with a deeper dive video: https://m.youtube.com/watch?v=zdJ9Tbm8ALg
We didn't give Jeff great direction on camera alignment calibration or setting the radio gain but he seemed to mostly figure it out. We're improving the UI based on his suggestions (it's open source so you can customize it too)
The RF augmented reality is just one of many applications of this brand new 4x4 MIMO software-defined radio built from the ground up. The AR uses a web app to stream RF points that your phone/laptop browser then live-merges with your local camera in the browser. I've been obsessed with low latency and high frame rate to make it a truly AR experience. More technical details at https://QuadRF.com/
Neat way to reduce cost and pin-count? But I think the typical FPGA clock tree has poor jitter performance. Not using the internal PLL(s) might help with spurs but the clock buffers are unavoidable.
The documentation mentions it's likely further degraded by noise from switching regulators. Oh the joys of hunting RF noise sources.
I have very little experience with MIMO / phased-arrays, this application likely doesn't need ultra high SFDR.
As I mostly deal with single channel applications, I get to use double superhet and avoid runtime calibration. Not an option here, Zero-IF has too much in the Pros column for multichannel.
Do you have a demo for that 240 elements assembly?
[0] https://www.prnewswire.com/news-releases/the-future-takes-fl...
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?)
https://www.fluke.com/en-us/product/industrial-imaging/fluke...
I think a few people have made homebrew versions too, like this one mentioned on HN: https://news.ycombinator.com/item?id=45137584
fluke $25k
flir $10k
td2 $1k
These are the kinds of things you look at and think - maybe I DO need night-vision, or a soldering iron with a cpu, or a thermal imager, or a steerable endoscope or now an acoustic imager....
https://x.com/ThermoInstagram/status/909356506059026432
Also for checking if microwaved food is ready.
Could one of these tools help map water pipe routes and trace a leak, or are they only going to be useful for air and gas leaks?
You should definitely try a thermal camera. Any moisture will create small temperature differences which are easily picked up by a thermal camera.
On balance, I would say this RF version was 200x harder.
https://www.youtube.com/watch?v=l8-5lSVCR2w
https://ribbonfarm.com/2016/06/29/the-daredevil-camera/
You need really high clock rate sensing to differentiate the arrival time for sound from microphone arrays where they are all less than a nanosecond separated from each other.
Very cool stuff, can be used for drone detection at up to 200m. Accuracy is not super good, unless you make mic spacing a bit large.
[1] https://www.youtube.com/watch?v=QtMTvsi-4Hw
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)
I've seen so many random industrial devices and parts come into our plant that have their own cellular it's wild.
In a television it's an added cost and it's unclear if serving ads really can offset that extra $25-100 of hardware (and included data) you ship on a $200-1000 television.
It's also unclear to me if the low data packages they come with would be enough to serve meaningful ads to begin with. Those devices usually come with a fixed plan of 100MB/month for 5yrs (or along those lines). Modern smart tv ads are very often video or at least hi res images.
Amazon seems to have done the math and found that it makes sense to give a $20 discount on a $180 device if it lets them display very unobtrusive ads on the lockscreen. So I don't think you are correct.
Not all mobile data APNs go to the Internet. You can't resell an IP service that lands on an RFC1918 network with exactly one IP:port available; the API endpoint.
Not saying I've seen this in devices, but I have built and run mobile data networks with private APNs.
Well... most TVs already have a WiFi/BT chipset for stuff like advertisements or, especially with Apple, high-bandwidth video streaming. There is already a radio module present, but (IIRC) you don't have to disclose what exactly that module is capable of.
There are some more advanced anti-drone measures at work: Like blasting them with directed high-energy microwaves to destroy the circuits.
So I’m pretty sure avoiding jamming by a military adversary is not trivial, even with frequency hopping and suchlike.
This is a bog-standard phased-array RDF calibrated for WiFi freqs; that stuff is already in every single defense show.
Also, that's why there's jamming everywhere (to blind that kind of things) and why many UAVs are now tethered to optical fibers instead of being RF-controlled.
The first phased array systems date back to 1905.
We have had some time to productionize this.
Hell, the "PA" in "PATRIOT missile" stands for "Phased Array".
Really depends; there you can see both Lockmart exhibiting multi-billions project, and 150m after some Serbian company selling jet engines for UAVs for a couple hundreds.
I had a friend who'd just gotten out of EE school as a non-traditional student who was working for a company that was making radars for tracking drones maybe five years before the 2022 Russian invasion.
That was an active system, similar in concept to the radars used in air defense system just scaled down and faster acting.
The one in this article is a passive system that sees the transmitter on the drone. The comm link is the obvious weak spot on the drone as it can be detected and jammed, it is fairly inevitable that lethal attack drones that work anonymously will be widespread as a result.
Isn't most drones run by fiber optic nowadays around the front-lines though? Can't really jam those, but maybe still detect it somehow?
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.
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.
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.
Why so bullish on government? The department of motor vehicles is capable of being better, but they aren't.
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.
Ah, found discussion of what exactly it was they pulled, it was the passive radar code: https://www.reddit.com/r/RTLSDR/comments/yu9rei/krakenrf_pul...
And indeed, they confirmed that they believe the open source software should be OK, but they had concerns because they also sell the compatible hardware: https://nitter.net/rtlsdrblog/status/1591657740229046274
Not always, but pgp wasn't exported that way until not long before there was good demand for for encryption in e-commerce anyway
> Direction finding equipment for determining bearings to specific electromagnetic sources or terrain characteristics specially designed for defense articles in paragraph (a)(1) of USML Category IV or paragraphs (a)(5), (a)(6), or (a)
ITAR part 121.
The "specifically designed for defense" probably makes this OK, but IANAL.
Title 22 Chapter I Subchapter M Part 121 - The United States Munitions List - Category XI Paragraph b
Electronic systems, equipment or software, not elsewhere enumerated in this subchapter, specially designed for intelligence purposes that collect, survey, monitor, or exploit, or analyze and produce information from, the electromagnetic spectrum (regardless of transmission medium), or for counteracting such activities.
Wouldn't that apply to every spectrum analyzer?
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.
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.
From documentation, QuadRF: Operating frequency range of 4.9 - 6.0 GHz (C-Band).
0. https://espargos.net/
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
It's a really neat device, but people should realize that it has a very narrow visibility.
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.
How are they planning on distributing a shared, highly precise clock for that purpose? That's already a PITA if you do QO-100 modes that need high precision, but usually there it's enough to have one good clock that you feed to the LNA... but here? Every single one of these modules needs a very precisely identical timing signal and the kind of chips you can use to multiplex a reference clock signal are pretty expensive.
They came out at $500
Being off by a bit is fine. Being off by 5x to 10x is.. Yikes.
See the 6-pack: https://www.crowdsupply.com/scale-rf/quadrf#products
[1] https://www.reddit.com/r/homelab/comments/1uso8u1/insanity/
[0] https://www.microcenter.com/product/702590/raspberry-pi-5?rd...
[1] https://www.adafruit.com/product/6125?src=raspberrypi
Point still stands that they initially said it would be $50-$100. And its going for $500.
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
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
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.
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
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...
This gizmo is primarily interesting that it's pre-packaged at a price that hobbyists can afford.
It does become a bit more difficult with consumer grade off the shelf drones because it's built in. Still defeatable by the determined of course.