Defense against UAV's

wrote:
The situation is analogous to that posed by the first Russian anti-ship
missile, the Styx. It was around for years and no-one took much notice
until one sank an Israeli destroyer in 1967 - then the USN woke up to
the need for a short-range defence system, and Phalanx was the eventual
answer.

Is that installed on the ship in question?

http://www.globalsecurity.org/milita...hip/cvn-76.htm
USS RONALD REAGAN is equipped with Rolling Airframe Missiles (RAM),
which replaces the Close-In Weapons System (CIWS) used on other
carriers. RAM Systems pack 21 fire and forget missiles capable of
destroying any high-speed incoming targets.

But how about low-speed incoming targets? Send in the Stringbags?

Better yet, assign each Carrier Strike Group an ESG for protection
against slow flying targets.

Why?

For the fighter aircraft that can hover in midair. VIFF 'em dead.

-HJC

schrieb:

The responses so far all point to several things:

snip
3. It is always likely to prove difficult to spot a small, stealthy UAV
by any means - visual, IR or radar. Furthermore, existing gun/missile
systems are not designed to engage such targets and may have great
difficulty in doing so.

What about using lidar?
In bad weather the drone/UAV might be degraded as well as your lidar-system.

And for defence/shooting them down maybe something like THEL could be
used, and I believe the range of THEL being superior to that of most gun
systems.

4. The UAV controlling station can be mobile and will only need to send
occasional very brief signals - they will require a lot of effort to
locate and kill.

Basically it comes down to difficulties and probabilities. UAVs exist,
now, which are extremely difficult to detect and can carry the
necessary targeting equipment. They are very cheap by military
standards. Laser-homing munitions exist, now, which are cheap and can
home in on such signals. The means of dealing with such a threat does
not appear to exist at present. I have no doubt that people are working
on it, and that solutions will be found (perhaps along the lines that
some have suggested here), but they are likely to require a lot of cost
to implement and will always face the basic problem - the UAV
controllers only need to succeed once, the warship has to succeed every
time.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

wrote in message
oups.com...

Keith W wrote:
wrote in message
ups.com...


Hint: Look up the accuracy specifications of GPS.

In 7-10 years it will be Galileo. The specifications are a little bit
eklastic as they depend on integration time. If you are talking about
RELATIVE separation this will in fact be only a few centimers, the
accuracy of DGPS.


The accuracy of the GPS systems isnt the issue anyway. Its
handling the problem of separattion of large numbers of drones.

If they have to communicate with each other that introduces
extra weight, a considerable processing issue and a vulnerability
to jamming and/or spoofing.

Frankly you'd probably be better off accepting a certain percentage
of losses due to mid air collisions

Keith



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The issue of transmission is the ability of a controller to take
action.

You dont get it. To maintain separation each drone needs to know
where its neighbours are not just its own position

Also you need some degree of defense in depth. If an enemy
swarm approached you, you would need the ability to direct resources to
that are. One UAV with a LMG is not going to stop a swarm. If however
it had communication technoilogy it might.


The USN isnt going to rely on one LMG for defence

Acceptance of losses due to mid air collisions - OK there will be heavy
losses from a variety of causes. This is, of course, acceptable in a
cheap unmanned system.

To me the amazing thing is the sophistication of COTS. You talk about
weight and cost, but I can put a mobile in my shirt pocket which can do
the most amazing things. Spoofing - all converstaions are routinely
encrypted. Jamming - yes OK but if you are the US you simply put the
jammers out of action.


The US is doing the jamming in this scenarion and dont kid
yourself that encryption cant be broken.


In point of fact use of an error correcting code, such as Reed Soloman,
will go a long way to soving the problem of jamming. You transmit in
bursts, the jammers have be on all the time.


And this is a problem because ?

If you were to have a swarm of UAVs with slightly modified mobile
phones with some aircraft being base stations and commumicating via
satellite you would have gone a fair way to building your system
without too much reaearch.


Psst mobile phones require repeaters in line of sight, there arent
too many in the middle of the Gulf


Keith



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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? 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
proved to be capable of doing so. To take any other attitude would be
foolish complacency.

: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?


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.

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
pilot will have no idea where his shots are going.

:The basic problem is that naval self-defence systems are designed to
:deal with large, fast objects which produce a nice big radar echo. We
:know that they have problems picking up stealth planes - that's the
:whole point of stealth planes, after all - so it is obvious that
:they're going to have a hell of a lot more problems dealing with a very
:much smaller and inherently stealthy object. I don't doubt they will
:eventually find a means of coping with them, but that's probably years
:away - and the threat exists now.

Hint #4: The sky is NOT falling, Chicken Little....

I sincerely hope that you have absolutely no connection with the
planning of USN defence systems, because that sort of sneering
complacency gets the wrong people killed.

:Note that according to the website above concerning the half-hour
:terrorist flight over Israel "the Israeli army could also do nothing to
:shut down the plane though they observed the entire flight over their
:territory."

And just why was that? It's a preposterous claim. If you can see it
you can kill it.

How, exactly? Ordinary MGs with eyeball sights stand hardly any chance
of 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.

The report I referenced has this to say: "According to a statement of
Hezbollah leader, the flight over Israel to Nahariya lasted 14 minutes.
Israeli side confirms this claim."

The report also says: "Currently no country has an efficient defense
against small low-flying UAVs, because existing air defense systems are
not designed to counter threats of this type. Air defenses are mainly
aimed at relatively large and fast planes. Thus, it is not surprising
that Israeli air defense turned out to be weak against "Mirsad 1" UAV.
Israeli army could also do nothing to shut down the plane though they
observed the entire flight over their territory."

Unless you have evidence that the report is a fabrication - in which
case please post it here - what are your grounds for dismissing it,
except of course that you don't want to believe it?

:The situation is analogous to that posed by the first Russian anti-ship
:missile, the Styx. It was around for years and no-one took much notice
:until one sank an Israeli destroyer in 1967 -

And was totally ineffective only 5 years later, although dozens were
fired, with one even being downed by a 75mm gun.

That's right: the Styx was a very big and quite slow missile which made
a nice big target. Modern anti-ship missiles are in a completely
different league. Please note that the Israelis now fit Phalanx to just
about all of their warships.

:then the USN woke up to
:the need for a short-range defence system, and Phalanx was the eventual
:answer.

You have an interesting view of history is all I can say.

So please explain - why in your opinion was Phalanx developed?

Just to help you, I have a copy of an article by the US technical naval
historian Norman Friedman, which describes the Phalanx as "specifically
designed to destroy incoming missiles which have survived other fleet
defences."

Your basic attitude seems to be that the USN defences will work
perfectly as they do "in the movies", while their attackers will be
easily defeated. Try asking the crew of USS Stark about that. NO weapon
system, offensive or defensive, can be relied upon to work all of the
time, for a variety of technical and human failure reasons.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

In message om,
writes
Jeb wrote:
It would seem to me to be likely that a simple software code
modification would allow an Aegis system to detect smaller, slower
returns (I would expect that right now, those get filtered out so that
seabirds don't cause spurious readings on the radar scopes).

I doubt that very much. If radar systems have great difficulty in
detecting and tracking stealthy aircraft like the F-117, B-2 and so on
- big objects with lots of metal in them - they are going to find it
vastly more difficult to pick up a very small, mostly plastic object
which has also been designed to be as stealthy as possible.

It depends on the values of "great difficulty" you're working to. Being
able to knock the range of a D-band search radar down to a fraction of
its expected value, can open great gaps in a land-based radar network
through which a stealth aircraft can fly: but overflying a ship with
such a radar will still get you detected and tracked at quite usable
distances, even in a "Stealth" aircraft.

To simplify grossly, a radar can detect a target at a distance
proportional to the inverse fourth power of its radar cross section -
so, for example, a radar that can pick up a one-square-metre target at
100 miles, can spot something half that size at 85 miles, or a target
with a radar echoing area of 0.01 square metres at about 32 miles.

Big differences there between "get through the radar fence along their
border" and "fly over the top of the radar undetected".

If that
could be remedied by tweaking the software, then all of the money spent
on stealth aircraft has been wasted.

Stealth aircraft aren't generally trying to play Kamikaze into warships
at sea.

--
Paul J. Adam

In message , Fred J. McCall
writes
wrote:
:That's because ships haven't had to deal with UAVs before.

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...

:As someone
:else on this board has suggested, a helo with a machine gun may
:actually be the best way of dealing with small, slow UAVs

"Someone on this board" will inevitably suggest all sorts of stupid
things.

Hint #1: It's not a 'board'. Its called a newsgroup.

Hint #2: Helos are too slow to deal with even a slow UAV. The
leading edge of the rotor goes transonic at relatively slow forward
speeds.

Smaller UAVs, light civilian aircraft et cetera fly rather slower than
some helicopters - the Lynx has a higher cruise speed than many light
aircraft's "pass this red line and the wings fall off" Vne - and can
leave most of the smaller UAVs standing (top speed ~170kt compared to
ScanEagle's 60kt, for example). Or, more appropriately, intercept, hold
formation, and allow the employment of an M3M .50" machine gun from the
most appropriate range and angle.

After all, when conducting trials to work out what useful things a UAV
could do for your forces at sea, it makes sense to also check out what
unhelpful things an adversary might try to do with his own UAVs and how
they might be detected and if necessary dissuaded...

--
Paul J. Adam

In article ,
(Andrew Swallow) wrote:

A machine can get a fairly accurate bearing in 10ms. Machines
can be made to be very patient so the several minutes is only
a minor problem.

The point you are missing that has been made is that there is no
need for the transmitter to be at the same place as the command
post or the only one. If I was doing this I would have a command
post, fibre optic links to several transmitters and possibly the
transmitters using remote aerials. Combine that with random
transmitter selection for each transmission and it will make life
difficult. Oh eventually you will run out of usable transmitters
but the swarm is likely to be extinct by that point anyway.

The so called computer intelligence required by each UAV is a
much bigger problem.

Ken Young

On Wed, 31 May 2006 16:44:09 -0700, Mark Borgerson wrote:

Why are you assuming that the command post does not move? I see no
reason that a mobile command post and multiple mobile transmitters
could not be used.

"I see no reason why all of the problems with my idea can't
be addressed by making my system even more complex."

You already have a large number of Predator-sized UAVs (the
Predator has a wingspan of almost 50 feet and is about 28 feet
long, by the way, for a payload of about 450 pounds), which
are apparently equipped with a sensor suite that can image
ships in visible light and IR (it would kind of suck to not
be able to see your target several miles away in haze, or if
it was dark out, so I'm assuming you've already thrown in
multispectral imaging capability, or hey, why not synthetic
aperture radar) plus a laser rangefinder and sophisticated
ESM receivers that can classify and locate enemy radar emissions,
plus a Mk 1 Electronic Brain that can fuse all the sensor data,
analyze images to reliably identify specific ship types from any
angle and in any lighting conditions, and decide all by itself
to engage targets with the weapons that also somehow have to
fit in that 450 lb payload.

Oops, I almost forgot the swarm of decoy aircraft that match
the radar, IR, visual, and ESM signature of your real attack
UAVs (so the enemy can't easily classify them as decoys and
ignore them), but are just there to make things more confusing.

Now you want to add a mobile command infrastructure, presumably
with a horde of mobile decoy transmitters to make the actual
transmitters harder to target (if the decoys aren't mobile,
after all, they won't be very effective decoys.)

What happens if the ships you're trying to attack are below
the horizon from your coast? Better add a satellite
communication system so you can still order your UAVs
around when they're more than 20 miles offshore.

Or hey, wait a minute, the UAVs are autonomous, so why not make
them submersible too? If they're attacked, they can just dive
into the water and continue the rest of the way to the target
safely. At one stroke, you've just rendered all of the enemy's
sophisticated air defense systems useless!

I think there might be a point somewhere in there when the
leaders of Ashcanistan will tell you and your Asymmetrical
Warefare-O-Matic system to get lost, and go back to their
original idea of using WWI-era naval mines and suicide
speedboats to inconvenience the naval forces of the
Great Satan.


ljd

"rb" wrote in message
...
wrote:
According to:

http://en.rian.ru/onlinenews/20060530/48833304.html

An Iranian UAV was able to circle a U.S. aircraft carrier undetected
for 25 minutes.

With U.S. forces making increasing use of UAV's, the inevitable
question becomes:

How can we protect our forces against UAV's when other countries or
terrorist organizations start using them against us?


Highly unlikely that it went undetected for 25 mins.
More likely it's Iranian sabre rattling again.

rb

Indeed. How would they have known it wasn't detected for 25 minutes after
detecting it after all

"Jim Yanik" wrote in message
.. .
wrote in
ups.com:

According to:

http://en.rian.ru/onlinenews/20060530/48833304.html

An Iranian UAV was able to circle a U.S. aircraft carrier undetected
for 25 minutes.

With U.S. forces making increasing use of UAV's, the inevitable
question becomes:

How can we protect our forces against UAV's when other countries or
terrorist
organizations start using them against us?


Was the Iranian "UAV" a small drone like ours,or was it a FULL-SIZE
aircraft that was remote controlled?

most likely it was a genie out of some Persian story, and dreamed up by some
Russian journalist.