The real problem with defence against drones

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A blog post about the real drone problem is overdue because I do not see ANY indication that the real problem is part of the public discourse. As a consequence, there's severe misallocation of resources.

 

Imagine you're driving a vehicle through a typical European landscape. This is a VERY different landscape than military training grounds, by the way. There are trees, bushes, ditches close to roads, buildings, fields with tall (more than 30 cm high) crops, enough garages to hide a SUV-mobile company per village, there's scrap lying around.

You pass by one of the gazillion trees, it's still 50 m away. Your vehicle is equipped with all kinds of drone detection sensors imaginable such as visual spectrum optornics, NIR, MWIR, LWIR, mmW radar, acoustic, broadband frequency analysers. A quadcopter is accompanying your vehicle at 100 m altitude, it pattern recognises threats and a buddy of yours in the vehicle checks the reports. Suddenly, you're dead.

What happened? A drone that attached itself to the backside of a tree heard your vehicle approaching, swung its sensor and EFP around the tree stem and fired an EFP warhead at you. No hard kill APS stands a chance of stopping that. The overhead drone saw nothing. 

source https://www.researchgate.net/publication/382231382_Crash-perching_on_vertical_poles_with_a_hugging-wing_robot

What "C-UAS" defences could have protected you? Some 70 mm rocket with semi active laser seeker? Some 30 or 35 mm autocannon with radar and thermal imager fire control? Some laser? Some microwave beam weapon? No, not even the kind of defence that I argued for since 2017 -a CUAS RCWS with machinegun or at most a 20 mm autocannon- could have saved you.

A lot of passive and reactive protection would easily have stopped that EFP attack, of course.

EFP attack; a shaped charge with 110° or more opening angle

 

Now suppose it wasn't one tree, wasn't one drone and it wasn't using an EFP. It was a patch of woodland or some bushes or a plowed field with drones hiding under soil. There were 30 drones with Faraday cage protection against microwave attack. They rise suddenly, overwhelm the APS with a series of attacks and hit the top of your vehicle with 70+ mm (500+ mm RHAeq) tandem shaped charge warheads.

Again, you're dead. There were more than 20 penetrations because no vehicle can be protected against this with enough passive and reactive armour.

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I believe I thought this through enough since 2017.

There's no line of sight defence against this.

We need to emphasise the thousands of years-old* concept of security effort

instead of staring at line of sight defences.

The traditional security effort would require to send men out, expose them to great risks to reduce the overall risk to the total force. That seems nonsensical now. We should send out drones as security effort, to search for, warn about and if possible neutralise hostile drones at a safe-enough distance.

Even a single car moving through hostile terrain would require a security ring around it, possibly at 200 to 2,000 m distance. Experiments will tell what the required radius is. Different terrain will require different security efforts and likely different sensors carried by the security force drones. So there would be a constant change of the security ring while that manned car is moving. The ring would become densified where needed, thinned out where that's acceptable, change of terrain from woodland to ploughed field would lead to a major change of what drones are scouting. The security force drones may even open and inspect buildings, weld shut manhole covers with thermite. The control software that controls the drones would report possible contacts, but it would also indicate the acceptable speed. It would need to be able to adapt to a change of route quickly. These security drones can look behind, under, into things. They can scan the ground - hostile drones may hide in loose soil such as mud and ploughed fields.

That's a LOT of effort for a single car. So mastering this AND having the ability to fend off a saturation attack of thousands of drones coming in one pulse (reminiscent of American carrier defence concepts of the late Cold War) is a huge effort. This leads to two conclusions:

1. A frontline with such a defence is much cheaper (and MUCH more reliably and more easily secured while static) than defending many individual areas all-round.
2. Any offensive movement in pincer-style or in form of a raid would have to be substantial. I estimate a brigade-sized effort may be debatable.

Conclusion #1 in particular would lead to a sizeable no man's land between human troops** and indeed between opposing high value hardware as well. The defender's advantage is slight when security drones fight security drones. Quality differences need to be substantial to matter much and even then they'd be unlikely to compensate for a factor three difference in production output. The party with the greater drone mass production capacity (and ability to supply the front with said drones) would win in a prolonged conflict. The peacetime inventories would matter for the first days, maybe weeks. The superior side could ruthlessly intensify the clash to quickly deplete the opposing drone forces. 

To be honest, I did not think all such consequences through yet. 

It's probably not necessary anyway, for it's rather unlikely that war happens when neither side has a qualitative edge or either side has a known qualitative or quantitative superiority that cannot be overcome. Defences could be shifted towards becoming impossible to occupy for long in such a case, preserving freedom only rather than freedom and civilian hardware.

Conclusion #2 is probably mostly relevant for the first days when a frontline is not fully established or if the inferior side wants to win by invading quickly. Another possible period of relevance is after the opposing party's drone forces were largely depleted, offering the opportunity to strike with a manoeuvre force without becoming overwhelmed.

 

The legacy arms industry wants to make the big buck with the kind fo hardware it understands: Big, expensive sensors and weapons; lasers, microwave weapons, autocannons, radars, big thermal imagers. This approach can sweep the sky between 100f t and 15,000 ft altitude just fine. It's not going to be enough. It's not even enough to protect against the fibreoptic FPV drones that laid in ambush next to roads in Ukraine months ago already. The focus on attention on above treetop line of sight C-UAS is badly misguided in regard to the battlefield. It's at most suitable to reduce the effect of strategic attacks.

S O

defence_and_freedom@gmx.de

 

*: See Xenophon

**: Compare the movie "Screamers" https://defense-and-freedom.blogspot.com/2008/01/screamers.html  

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