Defense against UAV's

In message , Fred J. McCall
writes
"Paul J. Adam" wrote:
:In message , Fred J. McCall
writes
:Air targets are air targets. Helicopters are neither trained nor
:equipped to do air intercepts.
:
:Perhaps not in the USN, but there *are* other navies...

Really? Who? Of course the French come close, but other than them?
:-)

The only reason I can come up with to be training helicopters to do
air intercept work is a total lack of any ship much larger than a
destroyer. That's not a navy....

Sorry you can't think of a reason, but that doesn't mean there isn't
one.

A hint - destroyers max out around thirty knots, a Lynx can wind up to
~170 knots. Which is more suitable to investigate something like a
Cessna or a Robin that cruises at ~70kt and stalls at forty?

--
Paul J. Adam

"Paul J. Adam" wrote:

:In message , Fred J. McCall
writes
:"Paul J. Adam" wrote:
::In message , Fred J. McCall
writes
::Air targets are air targets. Helicopters are neither trained nor
::equipped to do air intercepts.
::
::Perhaps not in the USN, but there *are* other navies...
:
:Really? Who? Of course the French come close, but other than them?
::-)
:
:The only reason I can come up with to be training helicopters to do
:air intercept work is a total lack of any ship much larger than a
:destroyer. That's not a navy....
:
:Sorry you can't think of a reason, but that doesn't mean there isn't
ne.
:
:A hint - destroyers max out around thirty knots, a Lynx can wind up to
:~170 knots. Which is more suitable to investigate something like a
:Cessna or a Robin that cruises at ~70kt and stalls at forty?

An F/A-18. But you need a carrier for those.

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

In message , Fred J. McCall
writes
"Paul J. Adam" wrote:
:Sorry you can't think of a reason, but that doesn't mean there isn't
ne.
:
:A hint - destroyers max out around thirty knots, a Lynx can wind up to
:~170 knots. Which is more suitable to investigate something like a
:Cessna or a Robin that cruises at ~70kt and stalls at forty?

An F/A-18. But you need a carrier for those.

See? There *is* a reason after all!

--
Paul J. Adam

Mark Borgerson wrote:
In article ,
says...
wrote:

:
:Fred J. McCall wrote:
: wrote:
:
: : Hint #3: A fighter with a 20mm Vulcan will flat mess up a "small,
: : slow UAV" and actually has a radar on board so that he can see it and
: : some actual training on how to do an air intercept, neither of which a
: : helicopter has.
: :
: :Always assuming that the radar is capable of getting a lock on the UAV.
:
: No such assumption is necessary. It's not like in the movies.
:
:What makes you so certain that gunnery radar WILL lock on to a stealthy
:UAV?

What makes you think that fighter aircraft use gunnery radar?

:The UAVs are designed, after all, to avoid being picked up by
:radar. For defence planning purposes the assumption has to be that
:radar will not probably work against them, unless and until it is
roved to be capable of doing so. To take any other attitude would be
:foolish complacency.

Which means nothing, since a fighter attacking with a gun uses
EYEBALLS to get the target and they're way up close.

: :If not, his chance of scoring a hit is remote - the speed differential
: :is so huge that he could do no more than 'spray and pray'.
:
: Hint #1: What do you think the landing speed of a jet fighter is?
:
: Hint #2: Guns work off the pilot's eyeballs.
:
:And exactly how will the pilot aim his guns, if the radar gunsight
:won't lock on and the sights he's got are no better than WW2 standards?

He'll aim them the same way he aims them against anything else. Times
have changed since WW2 and no 'radar gunsight' is required.

:Hint #1: in WW2 the Luftwaffe found that only between 2% and 5% of the
:shots they fired hit the target - and they were shooting at B-17s! Now
:scale down the target size to a UAV with a wingspan of a couple of
:metres, and work out how much ammo would have to be fired to nail one.

About 5 rounds.

Hmmm, coming up behind a UAV with a 6-foot wingspan, the cross-sectional
area of the target might be only 1 or 2 square feet. How close does
the fighter pilot have to be to hit a 2 square foot target with 5
rounds?

:Hint #2: unlike the Luftwaffe's ammo, the current standard US 20mm
:aircraft SAPHEI shell, the PGU-28/B, does not have a tracer - so the
ilot will have no idea where his shots are going.

Nor does he need to. It's NICE to have radar, but it's hardly
necessary in order to score a lot of hits with a modern gun and HUD.
SNIP

Mark Borgerson

An idea occurs, why not use the the overpressure from a high speed pass
to upset the UAVs' guidance system? Done with wing tip pressure on V-1s
in WWII, if these things are to small for ammo use air pressure to tip
them over.

It is ok blithely saying image recognition software which is not as cheap or
as easy as you suggest even if it was I would counter your Imgae recognition
with WW1/WW2 technology ie all the ships make smoke and turn into their own
smoke screens lol!

DD


wrote in message
oups.com...

Keith W wrote:
If you are using video imaging (backed up by some other, e.g.
IR/passive EM sensors),
I suspect it is a graduate student's exercise in image recognition to
distinguish a warship (esp. aircraft carrier) from an oil
rig/tanker/finshing ship. Especially if you are flying slow.

As a software engineer I'd suggest you are wrong. If such recognition
is so easy how did an Argentine aircrew drop bombs on an
American tanker in 1982 believing it was a RN Carrier ?
Scared ****less of being shot down?
Wishful thinking?
Orgasmic about being able to release their weapons and claim kills?
Darkness/lousy weather/bad visibility?
Flying fast and having only few short seconds to make decision?
Releasing their weapons from way too far range for positive
identification (perhaps because being scared ****less)?

Can be any of these or their combination.

A UAV with realtime video image recognition and IR sensors is unlikely
to be especially cheap
Realtime video image recognition needs a source of video (probably a
wide-angle search camera + narrow angle scope with some decent
magnification for examining the suspicios contacts), a decent CPU to do
the number crunching and a software to do the analysis. The first two
items are not particularly expensive. The software might take real
pains to develop, but afterwards the copies are free. Perhaps the
costliest part of the development would be sea trials (to see how is
the real-time identification working and debug it), but then who knows
what they use their small UAVs for now (see the first message of this
thread).

snip
200 km/hr UAV's are going to be rather vulnerable to all forms
of active defence including point defence missiles like RAM
and to CIWS.
Yes. That's why you want them to be really cheap and use swarming.

With real time image recognition systens cheap will be quite a trick.
The cost might be high for initial development, but there is not reason
the cost should be high on per-unit base. Cameras/CPUs and copying
software is cheap. Cooled IR sensors and other fancy sensor stuff might
rise the cost - the question is how much of it is needed, especially
if you don't ask for all-weather capability.

On
the other hand RAM is IR homing and the IR signature of a 100hp piston
engine is negligible compared to the IR signature of a rocket/jet
engine of the current antiship missiles.
But not small enough to be invisible
Nothing is invisible. But if its signature is there with seagulls and
sun reflections off waves, the locking/homing task is so much harder.

Phalanx (or other gun-based CIWS) should be effective, but has rather
short range (and not THAT much reloads, if you are dealing with a huge
swarm). I suspect it is also looking at targets with much higher radar
signature and very different characteristics.

Thats just software and rather easier to do than deciding if
that 1000 ft long ship is a carrier or VLCC
An attacking UAV can make its decision to attack close enough - when it
can actually see the island/aircrafts on deck of the carrier. And has a
lots of frames to base its decision on. It might even send some info to
the controller and ask whether to attack or not (again, tradeoff
between how much you send and how reliable you want your communication
channel to be).

The CIWS mounts look rather distinctly and will obviously be among the
targeted areas of the ship. You don't need that much of a warhead to
put CIWS radar ot of commission - so perhaps an UAV with 200kg warhead
can actually carry 8-12 short range missiles designed for homing on
CIWS radar and launch them while being out of range of CIWS.


Earth Calling Planet Esteban - a UAV with 200kg warhead and
8-12 sub missiles will be neither small nor cheap.
Such an UAV will not be small: it will be Predator size, powered by a
Rotax, Jabiru or more likely cheap copy of them. But it can be cheap,
especially if mass produced and intended for one-way cruise-missile
type missions. Ultralight aircraft kits are essentially hand-made and
sell for 10-20k. Replace the cabin with the warhead(s), give it faster
wing (no need for low stall speed, this is on one way mission) and the
sensors/brains/communication kit and mass produce it. Be smart
designing it (ease of mass production) and try to reduce the IR/radar
signature, but don't go overboard with that - keep the costs down. The
only potentially expensive parts on the aircraft are sensors and
warheads. The 200kg is the total useful load, some UAVs will have it
divided as sub missiles for massed attack on air defense radars, other
UAVs will simply have a big explosive load (hoping that the radars have
already been damaged, so they can get in close to do BAM).

...
simple systems are easier to debug/design correctly). However, a
country like China/India or even Iran should be able to mass produce
good enough UAVs for peanuts (i.e be able to field thousands of them).
The key term being 'good enough', not 'super duper, all weather, high
reliability and long service life'.

But with real time image recognition, organic SEAD and large warheads
Yeah, you need real time image recognition. That is the enabling
technology. I think we can agree to disagree whether that is possible
in the next 5-10 years, for operation in good visibility.

The quoted 200kg was just quoted as an example - about what an
ultralight aircraft can carry. You need your aircraft big enough to
have enough range to engage the carrier group operating off your
shores, so a 200kg payload will not significantly increase it anyway.
A modified ultralight can't fly that fast, leaving it rather
vulnerable. That's why you are better of launching submunitions from
out of range of the gun CIWS. Those subminitions need to be reasonably
smart (once qued by the sensors of the main craft, they need to be able
to lock on their target and hit it), but not necessarily pack a lot of
punch (hitting radars, aircraft on deck and so on). Once the radars
have been damaged, the second wave can then just press on with large
warhead bringing general destruction. (Or, to keep it simple, they all
go together. If the radars are switched off, the large warheads will
arrive and do the damage, if the radars are on (likely), the
submunitions will home on them.)


DUH !

Keith

Dave Deep wrote:
It is ok blithely saying image recognition software which is not as cheap or
as easy as you suggest even if it was I would counter your Imgae recognition
with WW1/WW2 technology ie all the ships make smoke and turn into their own
smoke screens lol!

DD


wrote in message
oups.com...

Keith W wrote:
If you are using video imaging (backed up by some other, e.g.
IR/passive EM sensors),
I suspect it is a graduate student's exercise in image recognition to
distinguish a warship (esp. aircraft carrier) from an oil
rig/tanker/finshing ship. Especially if you are flying slow.

As a software engineer I'd suggest you are wrong. If such recognition
is so easy how did an Argentine aircrew drop bombs on an
American tanker in 1982 believing it was a RN Carrier ?
Scared ****less of being shot down?
Wishful thinking?
Orgasmic about being able to release their weapons and claim kills?
Darkness/lousy weather/bad visibility?
Flying fast and having only few short seconds to make decision?
Releasing their weapons from way too far range for positive
identification (perhaps because being scared ****less)?

Can be any of these or their combination.

A UAV with realtime video image recognition and IR sensors is unlikely
to be especially cheap
Realtime video image recognition needs a source of video (probably a
wide-angle search camera + narrow angle scope with some decent
magnification for examining the suspicios contacts), a decent CPU to do
the number crunching and a software to do the analysis. The first two
items are not particularly expensive. The software might take real
pains to develop, but afterwards the copies are free. Perhaps the
costliest part of the development would be sea trials (to see how is
the real-time identification working and debug it), but then who knows
what they use their small UAVs for now (see the first message of this
thread).

snip
200 km/hr UAV's are going to be rather vulnerable to all forms
of active defence including point defence missiles like RAM
and to CIWS.
Yes. That's why you want them to be really cheap and use swarming.

With real time image recognition systens cheap will be quite a trick.
The cost might be high for initial development, but there is not reason
the cost should be high on per-unit base. Cameras/CPUs and copying
software is cheap. Cooled IR sensors and other fancy sensor stuff might
rise the cost - the question is how much of it is needed, especially
if you don't ask for all-weather capability.

On
the other hand RAM is IR homing and the IR signature of a 100hp piston
engine is negligible compared to the IR signature of a rocket/jet
engine of the current antiship missiles.
But not small enough to be invisible
Nothing is invisible. But if its signature is there with seagulls and
sun reflections off waves, the locking/homing task is so much harder.

Phalanx (or other gun-based CIWS) should be effective, but has rather
short range (and not THAT much reloads, if you are dealing with a huge
swarm). I suspect it is also looking at targets with much higher radar
signature and very different characteristics.

Thats just software and rather easier to do than deciding if
that 1000 ft long ship is a carrier or VLCC
An attacking UAV can make its decision to attack close enough - when it
can actually see the island/aircrafts on deck of the carrier. And has a
lots of frames to base its decision on. It might even send some info to
the controller and ask whether to attack or not (again, tradeoff
between how much you send and how reliable you want your communication
channel to be).

The CIWS mounts look rather distinctly and will obviously be among the
targeted areas of the ship. You don't need that much of a warhead to
put CIWS radar ot of commission - so perhaps an UAV with 200kg warhead
can actually carry 8-12 short range missiles designed for homing on
CIWS radar and launch them while being out of range of CIWS.


Earth Calling Planet Esteban - a UAV with 200kg warhead and
8-12 sub missiles will be neither small nor cheap.
Such an UAV will not be small: it will be Predator size, powered by a
Rotax, Jabiru or more likely cheap copy of them. But it can be cheap,
especially if mass produced and intended for one-way cruise-missile
type missions. Ultralight aircraft kits are essentially hand-made and
sell for 10-20k. Replace the cabin with the warhead(s), give it faster
wing (no need for low stall speed, this is on one way mission) and the
sensors/brains/communication kit and mass produce it. Be smart
designing it (ease of mass production) and try to reduce the IR/radar
signature, but don't go overboard with that - keep the costs down. The
only potentially expensive parts on the aircraft are sensors and
warheads. The 200kg is the total useful load, some UAVs will have it
divided as sub missiles for massed attack on air defense radars, other
UAVs will simply have a big explosive load (hoping that the radars have
already been damaged, so they can get in close to do BAM).

...
simple systems are easier to debug/design correctly). However, a
country like China/India or even Iran should be able to mass produce
good enough UAVs for peanuts (i.e be able to field thousands of them).
The key term being 'good enough', not 'super duper, all weather, high
reliability and long service life'.

But with real time image recognition, organic SEAD and large warheads
Yeah, you need real time image recognition. That is the enabling
technology. I think we can agree to disagree whether that is possible
in the next 5-10 years, for operation in good visibility.

The quoted 200kg was just quoted as an example - about what an
ultralight aircraft can carry. You need your aircraft big enough to
have enough range to engage the carrier group operating off your
shores, so a 200kg payload will not significantly increase it anyway.
A modified ultralight can't fly that fast, leaving it rather
vulnerable. That's why you are better of launching submunitions from
out of range of the gun CIWS. Those subminitions need to be reasonably
smart (once qued by the sensors of the main craft, they need to be able
to lock on their target and hit it), but not necessarily pack a lot of
punch (hitting radars, aircraft on deck and so on). Once the radars
have been damaged, the second wave can then just press on with large
warhead bringing general destruction. (Or, to keep it simple, they all
go together. If the radars are switched off, the large warheads will
arrive and do the damage, if the radars are on (likely), the
submunitions will home on them.)


DUH !

Keith


Counter with the finest image recognition equipment every made,
closely tied into a high-capacity combined memory and processing unit.
And still the Japanese and American pilots thought they had sunk
aircraft carriers and battleships when they actually missed tankers and
destroyers.

In article ,
says...
Mark Borgerson mborgerson.at.comcast.net wrote:

:In article ,
says...
: wrote:
:
: :
: :Fred J. McCall wrote:
: : wrote:
: :
: : : Hint #3: A fighter with a 20mm Vulcan will flat mess up a "small,
: : : slow UAV" and actually has a radar on board so that he can see it and
: : : some actual training on how to do an air intercept, neither of which a
: : : helicopter has.
: : :
: : :Always assuming that the radar is capable of getting a lock on the UAV.
: :
: : No such assumption is necessary. It's not like in the movies.
: :
: :What makes you so certain that gunnery radar WILL lock on to a stealthy
: :UAV?
:
: What makes you think that fighter aircraft use gunnery radar?
:
: :The UAVs are designed, after all, to avoid being picked up by
: :radar. For defence planning purposes the assumption has to be that
: :radar will not probably work against them, unless and until it is
: roved to be capable of doing so. To take any other attitude would be
: :foolish complacency.
:
: Which means nothing, since a fighter attacking with a gun uses
: EYEBALLS to get the target and they're way up close.
:
: : :If not, his chance of scoring a hit is remote - the speed differential
: : :is so huge that he could do no more than 'spray and pray'.
: :
: : Hint #1: What do you think the landing speed of a jet fighter is?
: :
: : Hint #2: Guns work off the pilot's eyeballs.
: :
: :And exactly how will the pilot aim his guns, if the radar gunsight
: :won't lock on and the sights he's got are no better than WW2 standards?
:
: He'll aim them the same way he aims them against anything else. Times
: have changed since WW2 and no 'radar gunsight' is required.
:
: :Hint #1: in WW2 the Luftwaffe found that only between 2% and 5% of the
: :shots they fired hit the target - and they were shooting at B-17s! Now
: :scale down the target size to a UAV with a wingspan of a couple of
: :metres, and work out how much ammo would have to be fired to nail one.
:
: About 5 rounds.
:
:Hmmm, coming up behind a UAV with a 6-foot wingspan, the cross-sectional
:area of the target might be only 1 or 2 square feet. How close does
:the fighter pilot have to be to hit a 2 square foot target with 5
:rounds?

He doesn't have to hit it with 5 rounds. He has to hit it with 1
round out of 5.

This source: http://www.simhq.com/_air/air_028a.html

Says that 80% of round will fall inside a 5-foot diameter circle
at 1000 feet. That's pretty good for a high-speed cannon in
an aircraft mount.

Now let's look at the math: out of 5 rounds fired, 4 will be inside
a 5-foot diameter circle. That's 4 rounds in an area of 78.5 square
feet, or about one round for each 19 square feet. I think that
means that there is a significant probability that all five rounds
will miss a 2-square foot target at 1000 feet range. At
much closer ranges, there will be a higher projectile density,
but tracking the target may become more difficult---particularly
if the small UAV is turning with a radius that the fighter cannot
match.

In any case, I doubt that only 5 round will be fired---more likely
something on the order of 50 to 60 rounds. That makes a kill
much more likely.


I also think that a high-speed pass with a miss distance of 50 to 75
feet would probably generate enough turbulence to disturb the
flight control system and probably overstress the airframe. Most
of the UAVs I've come across have fairly high aspect ratio wings
and cost concerns probably exclude titanium main wing spars! ;-)

This is probably not that difficult from hundreds of yards away. The
HUD shows him what the bullet path is going to be. Initially they'll
probably get FAR too close until they realize how small the targets
are.


That's true. And if you get too close, you will run into parallax
problems between the sight and the gun, if the gun is boresighted
for 1000 feet.

50 round at 500 feet ought to do the trick if the UAV is
flying in a straight line.


Mark Borgerson

"Paul J. Adam" wrote:

:In message , Fred J. McCall
writes
wrote:
::What makes you so certain that gunnery radar WILL lock on to a stealthy
::UAV?
:
:What makes you think that fighter aircraft use gunnery radar?
:
:The pilots say so.

snip

:Sounds like the gunsight uses radar, Fred.

Yes, I know, Paul. I work with pilots all the time. But it doesn't
HAVE to, the way the respondent was trying to insist that you HAD to
get a lock or you couldn't shoot.

snip

::The UAVs are designed, after all, to avoid being picked up by
::radar. For defence planning purposes the assumption has to be that
::radar will not probably work against them, unless and until it is
:roved to be capable of doing so. To take any other attitude would be
::foolish complacency.
:
:Which means nothing, since a fighter attacking with a gun uses
:EYEBALLS to get the target and they're way up close.
:
:And then the gunnery system uses RADAR to get the range input, and after
:a few seconds adds velocity, and after that accelerations, to take the
:gunsight from Level III (locked on, range available) to Level IV (full
:system functionality)

But you can still do it better than the "WWII" accuracy claimed, even
if you're pure visual. There are tics on the HUD that you can stick
the guy between if you have a rough idea of his size and you can get
the approximate range that way.

:The range becomes particularly significant when you're shooting at a
:target only a foot in diameter (like a ScanEagle seen from behind) - but
:your ammunition drops more than twenty feet over a thousand yards.

With something that small you'd be a lot closer. If you didn't
realize what it was you'd probably miss on the first pass (you'd be a
lot closer than you thought you were and would shoot over him).

::Hint #2: unlike the Luftwaffe's ammo, the current standard US 20mm
::aircraft SAPHEI shell, the PGU-28/B, does not have a tracer - so the
:ilot will have no idea where his shots are going.
:
:Nor does he need to. It's NICE to have radar, but it's hardly
:necessary in order to score a lot of hits with a modern gun and HUD.
:
epends on the size of the target and how long you have to shoot at it,
:doesn't it?

It's a slow UAV. Where's it going to go other than down, Paul? You
have all the time in the world to shoot it.

::How, exactly? Ordinary MGs with eyeball sights stand hardly any chance
:f connecting with a small plane at an unknown distance and travelling
::at an unknown speed, unless it comes very low and close. Radar FCS
::would probably not even pick it up.
:
:And none of that applies to most modern aircraft, or even most modern
:air defense weapons in general.
:
:Unfortunately we're not talking "most modern aircraft" when discussing
:such small targets.

Really? What do you think a CVBG is going to send out after them?
Butterfly nets?

:Assume the radar locks on, or that Dick Dastardly in the fighter is such
:an expert marksman he can hit by eye every time. A ScanEagle UAV is
:about a foot in diameter, seen from astern: a F-16's gun puts 80% of its
:rounds in a six-mil circle. At 1,500 feet, the target occupies only 1%
f that circle.

And you'd probably check fire until you got closer. It's not like it
can run away.

:Mathematically, if you fired an 86-round burst you would have a 50%
:chance of hitting it. To get the chance of a hit up to 95% takes you to
:a burst of 372 rounds, still assuming that the target remains in the
:six-mil circle throughout...

You're leaving out a factor. The rounds are not evenly distributed
through that six mil circle. They're still concentrated toward the
center. You need to work it as a Gaussian rather than a random spray
throughout the circle.

:This is the best case, assuming the burst is perfectly aimed throughout.
:Any errors - such as misjudging range because of a lack of radar lock -
:will make things worse.

Actually, it would probably make things better after the first pass,
since you'd be a lot closer. Probably miss with the first pass (shoot
over it judging by the visual range cues in the HUD because you'd
overestimate the range due to the small size) and get it with the
second pass.

Hell, fly close enough to it and it'd probably crash on its own just
from the turbulence.

--
"May God have mercy upon my enemies; they will need it."
-- General George S Patton, Jr.

"Paul J. Adam" wrote:

:In message , Fred J. McCall
writes
:"Paul J. Adam" wrote:
::Sorry you can't think of a reason, but that doesn't mean there isn't
:ne.
::
::A hint - destroyers max out around thirty knots, a Lynx can wind up to
::~170 knots. Which is more suitable to investigate something like a
::Cessna or a Robin that cruises at ~70kt and stalls at forty?
:
:An F/A-18. But you need a carrier for those.
:
:See? There *is* a reason after all!

Hence my mentioning NAVIES (and how forces with only destroyers don't
really qualify as same). :-)

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

"Arved Sandstrom" wrote:

:"Fred J. McCall" wrote in message
.. .
: "Arved Sandstrom" wrote:
:
: :"Fred J. McCall" wrote in message
: .. .
: :[ SNIP ]
: : I learned it the simple way: If you can see it, you can kill it.
: :
: :Well, not if "it" is capering about merrily in a No Fire Area.
:
: I can't say I believe in No Fire Areas.
:
:NFA's make sense if people remember what they are for. And if the target in
:the NFA is truly juicy, provoke them into firing on you; you are allowed to
:engage the enemy in an NFA for self-defense.

That's why it's "Hand of God" time when you get such targets.

One bullet - one kill.

[Of course, that assumes you have one of those guys around....]

--
"I know Slayers. No matter how many people there are around
them, they fight alone."
-- Spike, the vampire