Naval missile guidance thread - SAM systems
- Thread starter Iron Man
- Start date
Hello. I guess this is the good thread to ask this:
In a leonardo pdf, about their DBR for the PPA class, they go deeper in the characteristics and configurations of the radar arrays.
I would like to know what they mean by "SPK" and "MPK".
Maybe one of you radar nerd will be able to help me!
In a leonardo pdf, about their DBR for the PPA class, they go deeper in the characteristics and configurations of the radar arrays.
I would like to know what they mean by "SPK" and "MPK".
Maybe one of you radar nerd will be able to help me!
I don't think it's "module". Go to page 9 of your pdf, with the different Kronos Quad configurations, and you will see that for Quad 1000 and 2000, they say "TRM", while for Quad 3000 they use "2500 MPK-C". Also check the different shapes of the arrays; Quad 3000 is different from the first two. Maybe it's related to the "Active plate architecture" they're speaking about here too :
At least according to the CMO simulator, supersonics vastly outperform subsonics. I was shooting at PLAN ships with various ASCMs
Against the JSM, I got the following detection ranges:
Type 054 Top Plate radar: ~ 6.2nm (sunk with 2 salvos of 4 JSMs each)
Type 052D Type 346 PAR: ~ 7nm
Type 052D TV camera at 9.9nm (?)
Type 052D Type 517H-1 Knife Rest radar: 14nm-16nm (however, no firing solution with this radar)
- usually repels 5 salvos of 4 JSMs each, mostly just with HQ-10s. Rarely gets hit with 1 missile. Almost every defense missile hits the JSM. It looks like the JSMs are screwed by early detection by Type 517H which alerts the ship and allows it to engage as soon as the missiles are withing HQ-10 range or Type 346A PAR.
For the YJ-18 sprinting at 30 ft at Mach 2.8 the detection range was:
Type 346 PAR at 18nm. Could not engage with HQ-10s, as YJ-18 was above max target speed. First missile engaged at only 10 nm out (there is an inbuilt delay from first detection to engagement). HQ-9s frequently miss the target. Sunk in 2 out of 2 simulated runs against a 9 missile salvo.
For the Shipwreck missile, cruising at 60ft at Mach 1.5
Type 346 detects the missiles at 20nm.
- repelled a 20 missile salvo without hit
For the AS-4 Kitchen
Type 346A detects the missile at 83nm. Cannot engage at this range because the missile is cruising at 130,000 ft, above its max engagement altitude. As the missile descends down to target its speed exceeds Mach 5. Starts engaging at about 51nm out. Sunk in 1 out of 2 simulation runs against a 9 missile salvo ( 3 Tu-22s) . Expends 4 HQ-9s per every AS-4 hit.
Exocet Blk III
Type 346A detects the missile at 17.7nm
- engaging from 15 nm out.
16 missile salvo repelled. Every HQ-9 hit its target.
Last edited:
I tested that theory in CMO with a 150 kW Helios laser. The way they have it modeled, the laser needs a 3s dwell time to take out an incoming YJ-18, which it starts to effect from 15km away.
A supersonic missile already runs very hot at its forward section. The laser effector further heats up the fuselage, which leads to structural collapse due to high pressure from supersonic flight. Therefore, the laser dwell time against a supersonic may potentially be less than against a subsonic.
It may be doable to disable it eventually, but as I said, if that happens too late, you may still get hit and the KE itself could be enough to cost you serious damages.
I know how TVM works. It won't be called TVM if its command guidance. It means Track Via Missile and that means radar data from the missile takes priority. You're talking about range? Its about rate of closure, not range. Rate of closure is best calculated from data from the missile related to the target, than a ground station observing the missile from afar along with the target from afar. You do not 'refine' weak data with strong data, you disregard the weak data and rely only on the strong data. In this case this is not about the range resolution towards both the missile and the target, but the rate of closure between the missile and the target. Pulse compression is also an issue with earlier seekers due to the complexity of the circuit involved; CW is preferred because of its simplicity and reliability. The overall size of the circuits are much smaller and this matters especially to the bulkier Soviet era circuitry.
AIM-7M has a monopulse seeker. Its still a CWI. People toss around the word PD because it sounds cool but they don't really know what it means, and they don't want to bother knowing the difference between CW and PD. That's one reason when they see a Slotted Array antenna they call it PD, even if slotted arrays can be used for both.
It wasn't the first, nor it was something unexpected. Like literally, plane development included RCS measurement since 1940-1950s, and these planes were tracked by friendly radars all the time. The idea that they only SUDDENLY NOTICED that Mig is annoyingly blinky from the front from captured American pilots is a myth.
RCS studies date back to the very eve of the jet era and beyond - it was very quickly noticed, that the radar echo of different objects doesn't correspond with their size and that same objects reflect very differently in different bands. It was noticed literally everywhere where they worked on early warning radars during ww2.
Smaller RCS was a known advantage since forever, and by the 1960s was a well-understood advantage of smaller a/c with a less exposed engine over larger ones. The early US attempts to actually design a true stealth plane actually happened at the exact same time. They simply weren't possible w/o sufficient computing power and a proper model - and that only became available slightly later (Ufimtsev enters the chat).
Remember this pretty bird and her results?
Example of stealthy supersonic ASCM. Onyx certainly isn't one, YJ-12 isn't either. LACM will do as well.
You don't have to explain basic principles of stealth - I guess veteran forum members know them by heart. The crux of the problem is that Harpoon(Kh-35) is operationally less detectable than Onyx, stealth or not. And even in the 2020s is troublesome enough, many decades after first coming to the scene.
Making radome angled instead of round doesn't magically make you sneaky beyond commercial press releases. Stealth is a lot of work, and being stealth and supersonic at the same time is many times harder still. For modern* ASCM applications, where we're limited by (1)nature of the use of the weapon, (2)price of single-use saturation weapon, (3)size limitations - it's either one or another.
*it would've worked with old Soviet fighter-sized monsters - and no wonder, Soviets actually worked on it. But Soviet Navy is gone.
Don't remember talking about Ground station.
Searching down low ensures you remain below the horizon., thus ensuring at worst that you and target will have a chance to see each other at the same time*. Simple as that. The efficiency of turbofan on an airframe with a lot of lift(lifting body+high ratio wings) + modern computers allows complicated search patterns, and even at subsonic speed missiles can explore a lot.
This is a widely promoted advantage, because, frankly speaking, it's quite obvious.
*but (1)missile is smaller than the ship, and (2)search pattern will be necessary only if no targets use radar (LRASM is a dual-band, after all).
LRASM is a convenient and reasonably well-understood go-to example for a modern stealthy ASCM.
We know almost nothing about the new YJ-83 with double band seeker, other than its existence and what appears to be /stealthier/ shaping.
Since basing argument on assumptions about largely unknown missile is inefficient - it's way more convenient to base an argument on a better-known quantity. LRASM in itself is indeed a very different weapon - which, frankly speaking, doesn't make too much sense aboard the ship either. But it doesn't affect its value as a reference point.
Possible advantages of YJ-83(with new seeker) over YJ-12 are:
1. Unification of secondary weapon between all frigate units. And we're building a normal frigate.
2. Substantially(many times) smaller size and weight - affecting both ship design and handling, including handling at sea.
3. Price (including readiness aspect - cheaper, numerous missile allows more actual, not electronic launches=better trained crews).
4. Better suitability for a typical firing situation of a ship-mounted ASCM (sneakier, much lower minimal range) in SCS/ECS.
5. Much better capability against smaller targets, which are abundant in seas around China.
6. Far better ability to identify targets in a target-rich theater. Remember the 2008 Mirage debacle? Miracle away from a war crime.
7. Good enough against the majority of targets (4-missile salvo will likely go though even against targets with AA)
8. Much better ECM resistance.
That's enough?
Actually I am referring that the RCS of Onix and YJ-12 might be potentially lower than that of the Harpoon or the YJ-83. Maybe its Jai Hind BS or something, but I heard, though without any evidence as I took it as an unsubstantiated boast then, that Oniks/Brahmos can achieve an RCS lower than 0.1m2 despite its size. My estimate of the Harpoon/YJ-83/Exocet kind of missile is that they are around 0.1 to 0.5m2 RCS. Reasons for the lowered Oniks RCS is covered intake, no internal turbine blade reflections, sharply angled nose and wings. No idea what a YJ-12 can achieve but it does have similar characteristics, along with angled intakes with intake deflectors.
YJ-83 (and NSM) is viewed as a much more precise tool for dealing with cluttered areas with more sea traffic, as well as clutter from littoral environments. For now, it makes a better complement to the Type 054A's mission. It doesn't mean its not capable of handling supersonic missiles --- Type 054A/P will equip CM302 which is the export version of the YJ-12 --- should the customer demands it. The ship is obviously built and over engineered with such options in the mind early in its beginnings. We have also seen the Shenzhen replace its 16 YJ-83s with an equal number of YJ-12s, and the same may happen to the Type 052B refits.
Ability to identify targets in a target rich theater and much better ECM resistance on the part of the YJ-83 over the YJ-12 is something made available with the IR seeker. In terms of pure radar seeker only, there is no inherent advantage or disadvantage between one or the other.
Last edited: