Defense against UAV's

wrote:

:Jack Linthicum wrote:
:
: A swarm of UAVs requires a swarm of controllers and a swarm of secure
: frequencies to accomplish that control. I wonder if a follow-on to a
: Shrike or ALARM would bother to hit the transmitting antennas and
: instead have a large enough warhead to take out the whole controlling
: facility.
:A swarm of current generation UAVs requires a swarm of controllers.
:
:A swarm of highly autonomous UAVs (perhaps better viewed as a swarm of
:ultra cheap cruise missiles accompanied by some stealthy UAVs with good
:sensor suites) launched on a 'kill everything that floats and
:resembles a warship'' need not.

You've eliminated controllers by assuming impossible software.

Things don't work like they show them in movies.

--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson

In article ,
says...
Mark Borgerson wrote:
In article ,
says...
Jack Linthicum wrote:
[snip]

I think that a spread spectrum burst type transmission can be
intercepted and given a rough bearing. The money to do this is
miniscule in comparison with making Trident missiles into hand
grenades.
The command post does not move between transmissions. Spread
spectrum/frequency hopping systems return to previous frequencies every
few seconds. Just use several bursts to home in on the transmitter.


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.


This comes down to the definition of mobile. If the command post stays
in the same place for half an hour it is static. A constantly moving
command post would need a vehicle the size of a bus to hold the
operators and long range transmitters, possible but hard to camouflage.

So you don't think the Iranians have buses or semi-trailers? Suppose
there are 100 semis on the coastal road. Which one do you target?

Spread spectrum and frequency hopping systems do use a finite number
of frequencies---but the sequence of freqencies used may not repeat for
many hours. That leaves you with a broadband collection problem
and having to sort out multiple emitters on the same bandwidth with
different hopping schedules. I suspect that is a problem handled
offline and after-the-fact, and not in real time. However, the
technology has probably advanced a bit in the 30 years I've been
out of the sigint world. ;-)

If we are trying to destroy the command post we do not need to receive
the entire message we can simply wait until that frequency is reused by
that transmitter. If the equipment is hopping over 100 frequencies it
should be back within the next 200 transmissions.

With spread-spectrum transmitters, the time spent at one particular
frequency may be only a millisecond or two. If you can provide a link
to a system that can accurately track a moving spread-spectrum
transmitter, I'd be interested in reviewing its specifications.

The problem with intercepting spread-spectrum signals is that the
receiver KNOWS where the next signal will arrive. It can tune it's
receiver software for that frequency. The intercept receive has to be
able to recieve ALL frequencies---and thus cannot use the same signal
processing techniques as a receiver that knows the sequence.

The computers will need programming to treat transmissions from two
widely separated locations as two targets. Home in on them one at a time.

How do you work with one continuously moving target transmitting on
256 different frequencies? I suppose it could be done with large
enough antennas and enough processing power on a number of different
ships. It's not going to be easy, cheap, or widely available, though.

Mark Borgerson

wrote:

:On 30 May 2006 21:54:32 -0700, 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.
:
:Maybe so and maybe not.

I'd bet against. Just because they didn't kill it doesn't mean they
didn't see it.

: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?
:
:UAVs radiate. Their controlling facility radiates. If you radiate
:you are detectable. If you can be detected you can be localized. If
:you can be localized you can be targeted.

I learned it the simple way: If you can see it, you can kill it.

--
"When you enter a room full of armed men, shoot the first
person who makes a move, hostile or otherwise. He has
started to think and is therefore dangerous..."
-- Colonel Paddy Mayne, co-founder of the SAS

wrote:

:If the report on the Iran UAV is accurate,

And how likely do you think THAT is?

Have you ever heard of HELICOPTERS being scrambled off an aircraft
carrier to intercept inbounds?

I think the Iranians were being watched the whole time and just
weren't smart enough to realize it.

In other words, it's the usual baseless chest thumping that typically
occurs in that region of the world.

--
"If you grab them by the balls, their hearts and minds will follow."
-- Chuck Colson

wrote:

: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.

Please send me that graduate student's name, address, and phone
number. I know some folks that would like to give him a job.

Hint: The real world isn't a Hollywood movie.

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

In article V%qfg.6218$JX1.2803@edtnps82,
says...
"Keith W" wrote in message
...

wrote in message
oups.com...
[ SNIP ]
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),

Problem 1 ) You have to process them to decide if they are suspicious

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.

Understatement of the year
[ SNIP ]

If he can show the image processing and recognition problem to be easy, his
soon-to-be net worth will be more than that of Bill Gates. In fact, he'll
hire Billy just to supervise the programming staff to write the queuing
software for his executive bathroom.

Despite humongous amounts of research being done over many decades, general
computer vision remains an intractable problem. To illustrate, it may be
impossible for a vertical photograph (satellite) to differentiate between a
parking lot surrounded by a board fence and with a few cars parked on it,
and a large building with a flat roof and large roof vents, both with roads
nearby and under conditions of shadowing.

Now, in this case we'd certainly have a rules base codifying the knowledge.
But even restricting the problem to that of finding ships in the open ocean,
it's still not that simple. At a typical distance and altitude, a lot of
those ship lines are actually curves, so your algorithms need to recognize
smooth curves as part of a ship definition. Hmmmm, what else at sea is often
a fairly smooth curve?

I have a photo (8 1/2 by 11") of most of 4th MEB at sea, either 1990 or
1991. Fourteen vessels (LSTs, LPDs, LSDs, LPHs, one LHA, and a hospital
ship - no UNREP ships) are depicted. Going off the length of the LHA (shown
at a significant oblique), my estimate (very rough) is that the formation is
5-6 km across and perhaps 3 km deep. Even compressed like this - it's a
formation in time of hostilities that surely makes captains nervous - it's
still a collection with lots and lots of empty space. The colour contrast
and the wakes, the very calm conditions and excellent vizibility (light
haze) will at least allow a decent software to identify the ships as ships.
Leaving aside the hospital ship, I don't see that classifying most of the
vessels in the photograph would be anything other than a [very] difficult
recognition problem. A human can do it quickly, especially if cued with the
knowledge that everything is a USN gator, but it would be a pretty expensive
program that reliably typed each target.

One wonders too if the supposedly small and cheap UAV with the purportedly
inexpensive but sophisticated image recognition system is also fixing the
precise 3-D attitude of the airframe and hence the camera in order to allow
for estimating sizes of the objects in the picture, and _their_ attitude.
Forget relying on the horizon - in my picture you can barely make it out
because of haze. And it would have to be really precise data in order to get
good dimensional info.

what's wrong with just sorting the targets in order of image size and
and allocating the UAVs on that basis. Do you think they will be
too worried if they get the hospital ship or an oiler instead of
the LPD?

What if you can't even see the wake, for one of several reasons? I'll give
the program three stars if it even correctly figures out what end of the
ship is which.

Does it need to know which end is which? I would just aim
for the center of mass.
Now let's suppose that I am somewhat harsh in my analysis. Let's say that a
relatively coarse resolution picture and a basic analysis alerts the
software to "blobs of interest", and then the vehicle + camera is commanded
to do what it needs to do to get high-res images, and a better routine
analyzes these. Given some near optimal pictures - nearly side-on to the
vessel - you'd have something to work with. But in order to gauge size,
you'd need to be at some moderate altitude to have good geometry, under
which conditions superstructure begins to blend into the rest of the mass,
not be outlined against sky. In any case, with a large, detailed image of
the target, you now encounter other recognition problems e.g what details do
I ignore?

It is not a simple problem.

You seem to be assuming that the enemy wants more information than
"3 big ships at coordinates x,y, speed X, on course B" For recon
information where you know the position of friendlies, that's probably
enougb to issue the targeting order.

Given traffic patterns in the Gulf, it ought to be pretty easy
to test whether your software can distinguish between 1000-foot
vessels and 100-foot vessels.

Mark Borgerson

Ken Chaddock wrote:


Block 1B CIWS has an infrared and optical tracker that would do nicely
against any UAV within it's range...the question is finding the UAV in
the first place. An Infrared search system with the ability to designate
to a B1B Phalanx would work quite well I think...

But a prop-driven UAV with a small engine and some attention to exhaust
masking would not be an easy IR target.

If all you want to do is locate and identify a ship, and beam an
illuminating laser at it to guide the incoming ordnance, then the UAV
can be very small and very hard to detect.

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

wrote:

:
:Jack Linthicum wrote:
: wrote:
: Jack Linthicum wrote:
: ...
: The mention was of swarms which implies swarms of signals
: not necessarily, if mostly autonomous UAVs are used
:
: which then implies if I have an ECM craft up and I get lots of radiation from one
: direction I will send a message to that source. The decoys may work the
: second time but not the first or third.
: ??
:
: The control point will be that, singular, one command directing all of the UAVs
: from one spot.
: Ever heard of fiber optics communications? Set-up multiple cheap
: antennas for communication, and link them with fiber optics to your
: safe hidden command centre. Why you guys always assume that the bad
: boys are dumb beyond recognition alludes me...
:
: What the hell is an autonomous UAV?
:An UAV that can fly itself using an autopilot (see cruise missiles) to
redefined destination,

This much is doable.

:look around and try to see and identify ships

You just departed our current reality.

:and perhaps asks the controller for help in making crucial decisions
attack/ignore/move elsewehere).
:
: and to what purpose?
:Increase survivablilty/success of the system. Little, low bandwidth
:communication = difficult to detect & jam.
:
: You need a unique signal for each aircraft otherwise they will all turn left at
: the same time.
:You are still thinking 'remote controlled airplane'. Think 'remote
:command'. The UAVs are capable of flying themselves, they just might
:need advice from time to time. You don't tell each single aircraft what
:to do exactly, you just send a message to the whole swarm: "20% of you
:attack the ship, priorities ar A,B,C, the rest go to box [X,Y] and
:search for targets there" Each UAV rolls a dice, if it is in the 20%,

And what do you do if they all roll '1'? How do you even know?

:it rolls a dice to choose among the identifiable targets on the ship
phased arrays, CIWS radars, bridge, aircraft on deck, catapult).

Back into another universe.

:They
:actual flying and execution of the commands is done autonomously. (It
:will be a bit more complicated, but this is the basic idea.)

A 'bit more complicated' indeed - to the point of requiring sensors
and software that don't exist in our universe running on hardware we
can't build.

: On the first shot you may hit a bunch of decoys but also
: the target or targets. Especially if the decoys must be deployed under
: the control of the central command. Second time the decoys may stay on
: and the command freqs shut down. Third time no one cares and fires
: enough weapons to take care of the site and the decoys.
:No decoys needed. The UAVs themselves are cheap enough so that would be
:waste. Perhpas you can have a hi/lo mix of UAVs with high end
:sensors/UAVs with cheapo sensors (as the sensors are likely the
:costliest part of the UAV), the cheapo UAVs acting as a sort of decoys
but still being able to inflict damage, just with a bit lower
robability.)

You REALLY need to get out more and stop watching so many movies.

: I have heard of fiber optic communications, those antennas will still
: radiate
:With autonomous UAVs, the radiation will be intermittent and low
:bandwidth. Using spread spectrum/frequency agility or whatever, it
:will be difficult to pick up out of the noise. And antennas are cheap
:and you can have plenty of them....

Yes, "or whatever" seems to paper over a massive quantity of
technological unlikelihoods and impossibilities.

: It's the occupation afterwards that is the sticking point.
:Well, I don't think US will be dumb enough to try to occupy Iran. But
:with Dubya you never know....

As if you hadn't said enough dumb**** things....

--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson

Fred J. McCall wrote:
wrote:

:If the report on the Iran UAV is accurate,

And how likely do you think THAT is?

Have you ever heard of HELICOPTERS being scrambled off an aircraft
carrier to intercept inbounds?

I think the Iranians were being watched the whole time and just
weren't smart enough to realize it.

In other words, it's the usual baseless chest thumping that typically
occurs in that region of the world.

And do have any evidence that it was being watched, or that helicopters
were scrambled to deal with it, or is that just "baseless chest
thumping"? Presumably the USN would have said something by now if they
had known about it all along?

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

wrote:

:
:Fred J. McCall wrote:
: wrote:
:
: :If the report on the Iran UAV is accurate,
:
: And how likely do you think THAT is?
:
: Have you ever heard of HELICOPTERS being scrambled off an aircraft
: carrier to intercept inbounds?
:
: I think the Iranians were being watched the whole time and just
: weren't smart enough to realize it.
:
: In other words, it's the usual baseless chest thumping that typically
: occurs in that region of the world.
:
:And do have any evidence that it was being watched, or that helicopters
:were scrambled to deal with it, or is that just "baseless chest
:thumping"? Presumably the USN would have said something by now if they
:had known about it all along?

Really? Why? I don't recall a press release every time we caught the
Russians.

The IRANIANS claim the helicopters were scrambled to intercept it.
This is part of my reasoning for putting it down to baseless chest
thumping.

Hint: Helicopters aren't used as interceptors.

--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn