Thread by @DuitsyWasHere

1/18 Okay. Now let's talk about what can be done to defend against this type of attack.

This is sort of pushing the limits of my knowledge, so please chime in if I miss something.

2/18 The methods for countering drones and cruise missiles can be broken into two broad categories:
Kinetic (guns, missiles, and lasers)
Electronic (jamming and spoofing)

3/18 The CIWS concept is not new, at least not in the naval realm. Sea-skimming anti-ship missiles have worried naval officers since the 1960's.

To counter this threat, CIWS were developed - gun systems and associated radars that can automatically detect, prioritize, and eliminate threats.

The US makes Phalanx, Netherlands the Goalkeeper, Russia the AK-630 & Kashtan/Pantsir-M (which have missiles and two cannons), etc

5/18 Missile-based CIWS are less common, although they have a longer range. The US has the Rolling Airframe Missile (RAM) & SeaRAM (with the Phalanx radar), Russia has Kashtan & Pantsir-M.

6/18 In terms of land-based systems, the Russians probably lead. The Tunguska and Pantsir gun/missile systems and Tor SAM system are supposed to have anti-drone & missile capabilities.

I haven't looked closely at the evidence coming out of Syria, though.

7/18 When the US needed a system to intercept mortar and artillery shells in the 2000's, they literally bolted a lightly modified Phalanx to a semi-trailer and slapped a generator onto it.

We bought 43 of them, but eventually selected the Israeli Iron Dome instead.

8/18 There's also Germany's MANTIS, based on the Rheinmetall (formerly Oerlikon-Contraves) 35mm cannon, Skyshield radar, and AHEAD projectile. I don't have any information on its operational use.

Lasers may be the ultimate solution, since they don't run out of ammunition and eliminate the need for trajectory calculations.

The US Navy is working on the AN/SEQ-3, and Russia has experimentally deployed the secretive Peresvet (so secretive we don't even know its purpose)

10/18 But lasers can be degraded by weather, and are power-hungry. The AN/SEQ-3 runs off of a ship's powerplant, and Peresvet is rumored to use a mobile nuclear reactor.

I have my doubts about the Peresvet's power source, although it is possible.

https://twitter.com/DuitsyWasHere/status/1110710483919601665?s=20

11/18 Now, electronic warfare systems. I am not including the various counter-drone "guns"; chances are, if you can see and track a suicide drone with the naked eye, it's a bit too late.

Also, I'm not sure how effective they are against multiple simultaneous targets.

GPS/GNSS-based systems are vulnerable to jamming (transmitting a meaningless signal that overpowers the real GPS signal) and spoofing (similar to jamming, but the fake signal overrides at least part of the real signal, so the target thinks it's somewhere else).
(Image: @C4ADS)

Iran's capture of a US RQ-170 apparently relied on spoofing.

My understanding is that the drone was spoofed into thinking it was back near its launch airport, when it was actually at an Iranian airbase. The drone followed end-of-flight programming and automatically landed itself

14/18 Rumor is that Iran used the Russian 1L222 Avtobaza system. The Russians are quite good at electronic warfare (Avtobaza isn't even their most recent system - now they have the Krasukha-4)

15/18 My understanding is that the US is investigating ways to deny enemy access to GPS on a local or regional basis.

One concern, though, is how such actions will affect other actors (airlines, aid organizations, civilians, etc).

16/18 Drones that are remotely-controlled or can accept orders or external signals, are also vulnerable to jamming and spoofing, although good encryption can help deter spoofing.

This is how most electronic counter-drone systems work.

17/18 This is one concern about the usefulness of combat drones (UCAVs) like Loyal Wingman in fights against peer and near-peer opponents.

18/18 Okay, that's all I can think of on this topic right now. Please let me know if I missed (or misrepresented) anything.

Shoot, I know what I forgot - the difficulties of dealing with multiple drones at the same time. Back to writing...

Had to do some other stuff, will get back to this. In the meantime, here is a great thread by @SimonHoejbjerg

https://twitter.com/SimonHoejbjerg/status/1175054932275281921?s=20

@SimonHoejbjerg 21/39 First, some corrections.
As @mgubrud pointed out, I should have used 3 categories - kinetic, electronic, and directed energy.

Also, the method Iran used to capture the US RQ-170 drone was never confirmed.

Second, as @SimonHoejbjerg pointed out in his thread, radar detection of small drones at low altitude and discriminating drones from noise/clutter are challenging.

But radar is probably the best option. Small propeller-driven drones are unlikely to have strong thermal signatures

23/39 Now, countering attacks by multiple small drones or cruise missiles.

I am going to ignore the detection/tracking problem, and look solely at dealing with multiple targets.

24/39 Gun-based CIWS have significant limitations against multiple targets. The problems are time and ammo. Mostly time.

Phalanx opens fire at 1000-1500 meters, Goalkeeper at perhaps 2000 meters.

25/39 Let's assume a (probably very) optimistic engagement time of 2.5 seconds. (0.75 sec for target acquisition and tracking, 1 second burst, 0.75 seconds to observe projectile impact)

(the Navy is really cagey about discussing Phalanx engagement times)

26/39 If the target drone flies at 75 m/s (167 mph), it will take 20 seconds to cover 1500 meters.

In that time, a Phalanx can theoretically engage 8 targets (except not really, because the last drone will be engaged right before impact)

How many drones attacked Abqaiq? Oh...

27/39 Granted, that is an enormous oversimplification (it assumes the drones all enter the engagement range at the same time, among other things)

Still, 75 m/s is very slow. Most cruise missiles fly at approximately 250 m/s.

28/39 So you'd need multiple CIWS.

Oh, and make sure there's nothing valuable downrange, unless your neighbors aren't bothered by sudden torrential downpours of half-inch tungsten projectiles.

29/39 Lasers have several advantages over guns (shorter firing time, shorter post-firing observation time because the laser beam travels at the speed of light), but they can still only engage one target at a time.

30/39 Mr. Petersen already covered missiles, so I'll just try to summarize:

Technically feasible, but using missiles costing hundreds of thousands of dollars to shoot down $500 drones is economically questionable.

https://twitter.com/SimonHoejbjerg/status/1175055003935002626?s=20

31/39 I will, however, talk about this system.

https://twitter.com/RobotWrangler/status/1174879308231241728?s=20

32/39 It uses microwave energy to fry the electronics inside of a drone or missile. Can hit multiple targets at once, with a range between 750 and 2000 meters.

But I have... questions...

33/39 First, that's a big microwave transmitter, similar in size to the Active Denial System (the anti-riot "heat ray"). I realize Thor uses a longer wavelength that doesn't cause immediate pain, but... umm, have they tested it for deeper microwave burns at close range?

34/39 Second, and more importantly, when you fry the electronics in a multicopter, it tumbles out of the sky. When you fry the electronics in a winged drone, will it veer off course and crash, or will it continue flying and glide straight into its original target?

(Hence why 20/30mm CIWS use solid projectiles instead of explosive shells. If you blow the wings off of an anti-ship missile 2km away, the warhead crashes harmlessly into the ocean. Blow the wings off at 6-700 meters, and inertia will carry the warhead into the side of your ship)

36/39 When engaging missiles or winged drones at close range, you really, really want to make sure to either detonate the missile/drone warhead or force the missile/drone onto a different course away from anything important.

37/39 So yes, high-power microwave systems have potential. The US has tested Thor, and the Russians may have tested a similar system at one point.
uasvision.com/2015/08/04/rus…

38/39 In terms of electronic systems, the Russians have apparently used some of their systems to counter drone attacks in Syria. I'm not sure if all of the capabilities described in this article are real, though.
defense-update.com/20180108_uav_a…

39/39 Overall, there is no perfect single weapon for countering cruise missiles and small suicide drones. An optimal system would include multiple weapons deployed such that they can support each other.

Again, corrections, comments, and questions are welcome.