SinoDefence Forum

lilzz

As the missiles getting faster and faster, would that physcial limit on interepting that either using weapons like SeaRAM and CIWS.

sure, the radar and IR detection can track the missile but can they knock it out as its speed increases.

Alot of current antiship missile can travel mach1 to mach 2 but what if they are traveling Mach5 to Mach6.

Let me illustrate a point. first talk about the CIWS.
the radar detects the missile at point A, now the gun is not going to shoot point A because by the time the bullets reach point A, the missile already left that point. So, the CIWS computer has to make extrapolation on where to shoot the missile at point B. But how does the system determine point B?
the missile might not travel at constant speed. so this extrapolation leave room for error.


secondly, on the intercepting missile like SeaRAM. let say SeaRAM has its radar and IR detection, and incoming missile also has its onboard radar, therefore, both missile are aware of each other. SeaRAM can't go too fast else they will pass the intercepting point before the target arrived. SeaRAm has to slow down and wait for the target come to the intercepting point.

Now, the target missile awares of the SeaRAM presence therefore, when it almost arrive at the intercepting point, it suddently increase its speed from MAch5 to Mach6 and zoom pass that intercept point...

Now SeaRAM has to catch up the target but it's slow and no match in speed against the hypersonic missile which feature special type of engines.

Therefore for hypersonic missile with variable speed and has onboard radar for situation awareness, it will give the SeaRAM and CIWS system trememdous headaches.

man overbored

CIWS has two radars on the mount. One tracks the incoming missile while the other tracks the outgoing stream of rounds. The fire control solution is pretty simple, make the two tracks collide. CIWS also has an outboard IR sensor precisely for use against the high mach missiles. The two great drawback of missiles like 3M80 or Kh-31 are their inability to maintain the low sea skimming altitudes of missiles like Harpoon or Exocet, and their great speed means their skin temps are so high they glow like the sun to a decent IR seeker. The IR seeker was added to CIWS as an additional source of aim point data, since it can sometimes see the missile before the radar might. Also, RAM has outstanding performance against such missiles. It's IR seeker is extremely good at discriminating a target from surface clutter and has plenty of range to do the job. RAM also has a passive RF seeker that will home on the radar emissions of the incoming missile's seeker if it uses active homing as 3M80 is known to use. RAM needs no fire control information from the ship to operate, it is fire and forget.
Btw, the USN operated Kh-31's purchased from Russia in the mid 1990's as a target drone. In actual use the missile never came close to achieving it's advertised performance and the Russian supplied missile rails were unsafe in our judgement. We had to modify some of our rails for the Kh-31 ( we called it MA-31 ) but the advertised speed and range were unobtainable. A high mach run burned so much fuel that max range was only 15nm. For our training we needed a minimum 45 nm flight. Boeing suggested five changes to the Russians to make the missiles meet our minimum requirements. These were rejected and the USN chose another system to simulate the notional high mach sea skimmer. The last two MA-31 were fired last year from Point Mugu.

Here is a page on it's replacement, the Orbital Sciences Coyote, a mach 2.8 target system.

http://www.designation-systems.net/dusrm/m-163.html

Here is an article on MA-31 showing it being fired from a QF-4 from Point Mugu. Notice the Russian launch rail on the wing of the Phantom. You can also see the missile sitting on real US Navy "yellow gear". Notice the paragraph about the drone "lacking the range and flight path accuracy", in other words it could not maintain the low altitudes we needed for training and weapons testing. Piece of crap.

http://www.designation-systems.net/d...pp4/ma-31.html

Russian supersonic "sea skimmer" cannot manage to fly below about 15 meters ( not feet but meters ) while a Harpoon flies at 2 meters. This and the low IR signatures are why the USN sticks with subsonic cruise missiles. They are actually far harder to detect than 3M80.

crobato

I think it was called Kh-31MA or something like that.

MA as in "Monkey Amerikanski".

__________________
"Lets do a thermal sweep."

lilzz

Let's analyze the situation in better detail. as for your quicky line, I don't quite get it.

Because your bullet tracking radar always looking for the previous launched round of bullets as reference and relaunch a corrected new round. So you talking about time for launch first round of missed bullet+ launch new round of bullet... there fore it's alway takes more time and lacking behind the radar tracking the missile, which doesn't have to launch anything mechanically and wait for feedback.

therefore, bullet tracking radar is the weaklink. so even if you intersect the two, you still have room for error especially against high Mach missile.


secondly, because the Missile has onboard radar which aware of the seaRAM closing in. How do you account when the target missile suddenly change speed and make a speed dash just when SeaRAM is just about the hit the interception point. You calculate the interception point based on the target missile's previous speed.

crobato

You're confusing the forms of tracking. There is lag tracking, where the track lags the target; prime tracking, where the tracking is maintained at the target's center; and lead tracking, where the radar anticipates the target's track and leads the target.

What the fire control system does is to take the readings of the track, get its velocity and direction, runs an algorithm then makes a guess where the target is supposed to be next. So it anticipates the target. Tracking algorithms have become a lot sharper over the years and so is the computing power to run them. With scans going ever faster, so is the number of readings, and the more readings you have, the higher the resolution, the more accurate is the lead track. Simply said, you get the best results when you have the most info.

Of course, it is not completely foolproof since the computer is making predictions and guesses. All this is happening in electronic speeds, and to an electron, something like a Sunburn would appear awfully slow.

As for your second question, yes, the missile can have its own measures that can be used to defeat defenses using evasive tactics. It can have an onboard radar receiver or RWR. Receivers can detect defensive radars and determine the state they are, because the waveforms of search, tracking, tracking for locking, target illumination, and whether its illumination by a surface illuminator for a SARH missile or the illuminator onboard an active guided missile. A change in the radar state can command the missile to do an evasive action, and remember this is electronic reflexes.

The answer to smart defenses are smart missiles. From here on, its anybody's guess who will win. Further along the evolutionary path, things like LPI techniques may also affect the fates for both attacker (LPI on seeker) and defender (LPI on surface radars and defensive missile guidance). ECM and RCS reduction are also factors.

__________________
"Lets do a thermal sweep."

lilzz

How does this relate to man overbored bullet tracking and missile tracking?
Let me guess.

prime tracking=target missile tracking ??
lead tracking=fire control system prediction??
lag tracking=bullet tracking ??

so, man overbored 's idea of intersection of missile radar + bullet radar=
prime tracking + lag tracking??
what's his idea of intersection relate to yours? would they ever interesect

also what if the missile throttle or vary its speed when it's being illumainated. therefore the fire control system can't predict what's next.

crobato

Bullets will fire in a stream ahead of the target, so they are trying to anticipate where the target is.

The anticipation may not be completely foolproof which is why you want to put as much lead into the air to increase your chances. Helping to increase your chances and reduce probability of errors include having guided projectiles and exploding projectiles in proximity (flak). Nothing is absolutely certain with errors and evasion and all, but you want to have the odds as much as in your favor.

__________________
"Lets do a thermal sweep."

lilzz

I see, it's also a prediction. Man overbored make it sound as if automatic with certainty. therfore I was confused for a moment.

like I say, if the missile vary its speed when illuminated, then make it harder to predict its next point. so the point the bullets anticipate could be wrong.

also, within the CIWS range, the target missile evasion action can be throttle its speed or slow down a bit and let the bullets fly by ahead. It's onboard radar can sense bullets are coming.

man overbored

Ok, one point at a time.

"secondly, because the Missile has onboard radar which aware of the seaRAM closing in. How do you account when the target missile suddenly change speed and make a speed dash just when SeaRAM is just about the hit the interception point. You calculate the interception point based on the target missile's previous speed."

The incoming anti-ship missile has no means to sense RAM. RAM uses passive guidance, IR and RF. It does not emit. The anti-ship missile senses the reflections of it's guidance radar off the side of the ship and homes on the reflected energy. The dives and spirals are programmed into the guidance package and the missile performs these at a certain range from it's intended target. The missile has no way to sense an inbound RAM and because they are so small these missiles do not carry the heavy pods of flares or other countermeasures that might spoof a RAM. By the way, these missiles with the exception of Klub whose testing so far has been somewhat unsuccessful, all travel at a constant speed on their run in. They do not accelerate or decelerate in flight, their turbojet fuel controls are very simple valves, on and off. Solid fuel rockets as used in C-801 and MM-38 for example cannot be throttled at all, they burn full power until exhausted. RAM uses proportional guidance like Sidewinder so it never engages in a tail chase.
CIWS has one radar that scans for the incoming missile. It has another missile that follows the outgoing stream of tungsten. The fire control solution is to rapidly bring the outgoing stream of tungsten on a collision course with a missile that is flying pretty much dead on at the gun. It isn't flying by the gun but directly at it. If the missle climbs or corkscrews the two radars follow their respective targets while the fire control moves the gun until the outgoing stream of tungsten meets the incoming missile.
One last point. All of this ignores electronic countermeasures. In all likelihood, if history is any guide, a missile will be spoofed by electronic countermeasures before things like RAM and CIWS come into play. During Operation Praying Mantis the Iranians shot quite a few Standard missiles at our ships and we used the SLQ-32 to decoy them all. We never had to use the CIWS. In the 1973 Arab Israeli war, the Israeli's defeated over 50 Egyptian and Syrian Styx missiles who's range exceeded Gabriel by 10nm through the use of electronic countermeasures. CIWS and RAM are not the first defense against incoming missiles. First comes the carrier's air wing, then EW, then the missiles and guns.

King_Comm

The biggest problem engaging hypersonic missile is reaction time, Mach 6 means the missile is traveling at 2km per second, the reaction time for a CIWS is around 7-8 seconds, the maximum engage distance for is usually 2km, so the CIWS has to be able to find, and lock on to the target 18km away, and it has less than one second to shoot at the target, if the missile is large and armoured, the rounds fired in that time may not be sufficient to bring it down. RAM is slightly better, it has a range of 6km, so it has 3 seconds to shoot at the target.

lilzz

why not? the body of the seaRAM is metal , it will reflect radar wave right?
Also, it's exhaust is also be detected by IR sensor. Unless you telling me SeaRAM is constructed like a B-2.

Target missile is active homing therefore no datalink, EW is no use.

As for CIWS, the question I like ask is do you need prediction?
If you asnwer No it will become a different ballgame. Yes or No is sufficient for this question.

Scratch

Never, ever, will a missile be armoured. Weight is an important issue, and armor is just not feasable therefore. A missile going M5+ at such low altitudes needs a LOT of fuel to travel any meaningfull distance, therefore it will already be big and heavy anyway. Unless a revolutionary new propulsion is discovered. That weight and extreme speed will also affect the missiles maneuverability and restrict evassive action.
If such a missile gets that close however, there will of course be a lot of debris hitting the ship with high momentum, even if it's hit by the CIWS bullets.


If an AShM detects it's being engaged, and if that'll even work, what do you exspect it to do? Evade the incoming RAM only seconds before the AShM hits the target? If it does, it pretty sure won't regain contact with the ship and miss. That's a win for the RAM. Furthermore, there's not much space on a missile for a powerfull EW suite, so jamming the RAM with a AShM is also somewhat theoretical.

Of course EW is of use. EW is not restricted to jamming data links, but also (active) radars, and a lot of other things. Your missile might then perhaps answer with home on jam. But that doesn't guarantee success either.

lilzz

what it will do when it senses SeaRAm is coming close. like varying its speed, so make it hard for you to predict its next point. or accelerate and make a dash in sudden move to pass your predicted interception point which is based on previous speed.

how do you jam a LPI radar which featured on board?

Scratch

Adjust to varying target speed is not a difficult task for an anti air missile, it constantly and nearly simultaneously calculates the intercept point and maneouvers accordingly.

A ship has enough space to carry a sophisticated ESM and EW suit. I'm absolutely no expert in that. But LPI does not mean it's impossbile to detect or jam it. A hypersonic AShM is way into the future, and over time there will also be new techniques available.

With that speed, I'm wondering if the missile won't create a plasma cone around the nose anyway. That would then interfere with the radar I guess.

lilzz

Yes, the target missile and the interceptor missile both can adjust the speed.
but remember, the target missile is the initiator, the interceptor is the reactor,
the target missile wait till the interceptor very close and then suddenly acclerate, so it's too late for interceptor to adjust, its' already overshoot and past the interception point. It's momentum will carry it far .. it's too late, the seaRAM can't recover once it past the point. It cannot try to turn around and try to chase down the hypersonic missile.

therefore, at close distance where the reaction time is small, the initiator has all the advantage espeically the "dumb" seaRAM where the SPY 1 radar has to feedback the information back to interceptor missile and then activate its speedchange and direction.

Well even if you make SeaRAM "smart" by having active homing, and has onboard cumpter to recalculate and predict a new interception point, it still reacting, it might not have enough reaction time if "sudden move" excuted by the target missile at close distance.

as for plasma, the radar doesn't have to be in the tip. It can be install underneath the missile's mid-section belly.