I don't see any professionals turning to this for EMC/EMI testing, they already have all the test equipment for that job.

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...

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.

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.

Yes, primary radar has been useful for detecting airspace incursions since 1939. Nothing new here.

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.

Only the ones that use radio for control. The fiberoptic ones are "dark" to this setup.

for lack of directonality?

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/

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.

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

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

Do share some more details please

Please elaborate. There are literary step-by-step videos on how to build these. E.g. https://www.youtube.com/watch?v=g3LT_b6K0Mc

The explanation may be spelled ITAR.

It looks like it has 4 tiles on it, no?

Prices have gone a little insane in the last year though too to be fair to them.