5 ms·

Current point defense systems are already capable of placing a 20mm round with a muzzle velocity of 1000m/s onto a falling mortar shell in the last three second

Current point defense systems are already capable of placing a 20mm round with a muzzle velocity of 1000m/s onto a falling mortar shell in the last three seconds of its flight time. How hard do you think drones are by comparison?

milesward 5y ago
ballistic trajectory versus active evasive behavior.
- filmfact 5y ago
  Exactly - mortars predictable trajectory against a background free of ground clutter make them easy to predict the future location of. A drone optimally randomly dodging at treetop height is a much more difficult target.
  - imtringued 5y ago
    Why the hell would you dodge at tree top height? That makes absolutely no sense. Just fly a few centimeters off the ground without dodging and no air defense is going to hit you in a civilian area.
- NovemberWhiskey 5y ago
  https://apps.dtic.mil/dtic/tr/fulltext/u2/a426717.pdf https://apps.dtic.mil/dtic/tr/fulltext/u2/a426717.pdf A target with a 300mm frontal diameter, capable of evading at 10g, is expected to require 6 rounds to achieve a P_hit of 0.5 at 200m range, based on the parameters of your typical Phalanx CIWS. Said Phalanx weapon system might fire a burst of 1s duration in such an engagement, which is 75 rounds. For a missile engagement, that's a problematic number, but for a drone that's probably only moving a few dozen m/s and carrying a small payload, it's an entirely satisfactory engagement. Phalanx is an early 1980s weapon system. The Army is going to be fielding directed-energy SHORAD systems next year, equipped with 50kW lasers.
  - davidgould 5y ago
    Phalanx usually has about 1500 rounds ready, so 20 drones at 75 rounds each will run it out. Phalanx is large, heavy, and costly, and can't be readily be used in built up areas at low angles. A few dozen m/s is probably a good estimate for quadcopter style drones, but low hundreds m/s should be easy for fixed wing drones, so at 200 meter engagement range (that paper makes it pretty clear that maneuvering targets are hard beyond that) there is only time to hit a few drones before they arrive. So maybe drone swarms will work even against current CIWS.
    - imtringued 5y ago
      >So maybe drone swarms will work even against current CIWS. Sure, but current drone swarms wouldn't.
- imtringued 5y ago
  Or just fly near the ground so that air defense will kill the target of the drone...
cma 5y ago
They could fly low: the tech isn't fully there yet but skydio drones show the potential.
okwubodu 5y ago
> How hard do you think drones are by comparison? Very. The calculation made for each round could be irrelevant before they travel 500m. Drones also have no obligation to approach at the same convenient high angle mortars do. 2-3 drones weaving between buildings faster than a human can aim? Sounds terrifying.
ceejayoz 5y ago
How would they do if the mortar shell engaged in rapid, unpredictable evasive maneuvers at low altitude behind cover most of the way?
antihero 5y ago
> Current point defense systems Which are available to how many militaries?
anonAndOn 5y ago
So what you're suggesting is instead flying in a giant predictable parabolic flight pattern, just dropping the drone in front of the actual targets and let the big cannon do the work? Friendly-fire/own-goal for the win.
jacquesm 5y ago
Actually, quite hard. Mortar shells don't suddenly change direction.
stubish 5y ago
It depends on how long it takes the weapon to lock on and align. If it takes 1s to work out the trajectory and fire, the drone just needs to change its trajectory every second. But I guess taking down a drone is not like taking out a mortar shell. It is probably much easier with some sort of flak or even launching a net.

milesward 5y ago

ballistic trajectory versus active evasive behavior.

filmfact 5y ago
Exactly - mortars predictable trajectory against a background free of ground clutter make them easy to predict the future location of. A drone optimally randomly dodging at treetop height is a much more difficult target.
- imtringued 5y ago
  Why the hell would you dodge at tree top height? That makes absolutely no sense. Just fly a few centimeters off the ground without dodging and no air defense is going to hit you in a civilian area.
NovemberWhiskey 5y ago
https://apps.dtic.mil/dtic/tr/fulltext/u2/a426717.pdf https://apps.dtic.mil/dtic/tr/fulltext/u2/a426717.pdf A target with a 300mm frontal diameter, capable of evading at 10g, is expected to require 6 rounds to achieve a P_hit of 0.5 at 200m range, based on the parameters of your typical Phalanx CIWS. Said Phalanx weapon system might fire a burst of 1s duration in such an engagement, which is 75 rounds. For a missile engagement, that's a problematic number, but for a drone that's probably only moving a few dozen m/s and carrying a small payload, it's an entirely satisfactory engagement. Phalanx is an early 1980s weapon system. The Army is going to be fielding directed-energy SHORAD systems next year, equipped with 50kW lasers.
- davidgould 5y ago
  Phalanx usually has about 1500 rounds ready, so 20 drones at 75 rounds each will run it out. Phalanx is large, heavy, and costly, and can't be readily be used in built up areas at low angles. A few dozen m/s is probably a good estimate for quadcopter style drones, but low hundreds m/s should be easy for fixed wing drones, so at 200 meter engagement range (that paper makes it pretty clear that maneuvering targets are hard beyond that) there is only time to hit a few drones before they arrive. So maybe drone swarms will work even against current CIWS.
  - imtringued 5y ago
    >So maybe drone swarms will work even against current CIWS. Sure, but current drone swarms wouldn't.
imtringued 5y ago
Or just fly near the ground so that air defense will kill the target of the drone...

cma 5y ago

They could fly low: the tech isn't fully there yet but skydio drones show the potential.

okwubodu 5y ago

> How hard do you think drones are by comparison? Very. The calculation made for each round could be irrelevant before they travel 500m. Drones also have no obligation to approach at the same convenient high angle mortars do. 2-3 drones weaving between buildings faster than a human can aim? Sounds terrifying.

ceejayoz 5y ago

How would they do if the mortar shell engaged in rapid, unpredictable evasive maneuvers at low altitude behind cover most of the way?

antihero 5y ago

> Current point defense systems Which are available to how many militaries?

anonAndOn 5y ago

So what you're suggesting is instead flying in a giant predictable parabolic flight pattern, just dropping the drone in front of the actual targets and let the big cannon do the work? Friendly-fire/own-goal for the win.

jacquesm 5y ago

Actually, quite hard. Mortar shells don't suddenly change direction.

stubish 5y ago

It depends on how long it takes the weapon to lock on and align. If it takes 1s to work out the trajectory and fire, the drone just needs to change its trajectory every second. But I guess taking down a drone is not like taking out a mortar shell. It is probably much easier with some sort of flak or even launching a net.