PLAN Anti-ship/surface missiles

Blitzo · Aug 7, 2022

Tam said:
Same family, CM is the export name, but they plan to get rid of these names in favor of YJ-83E because its way easier to explain what it is. Buyers want what the PLA is using and not some untried, export only weapon.

The canted nose appears to be using a digital infrared imaging seeker. What it does is to take the target image in infrared, match its pixel outline to a database of images, and once identified, homes in to it. This mainly meant against stationary or slow moving targets. This is a precision land strike weapon. This makes sense since a converted ASM for land strike is cheaper than a large dedicated cruise missile, and you can make more of these to a given budget.

The other nose is a dual active radar guided and infrared homing missile. The dome still has the traditional active guidance radar, and the infrared homing system is similar to what AAMs use. There's heat, it homes into that heat source. So if the missile is jammed by ECM or confused by chaff, it can revert to infrared mode and home in to what's hot on the target ship, and that's usually the funnel area, and when it does that, it will nail the engines. Infrared homing and infrared imaging should not be confused as the same.

Some ships are aware and prepared for infrared seeking in antiship missiles so they cover the funnel with an outer structure that allows ventilation to come in and cool the inner funnels. The outer housing also intends to hide the funnels. These design elements are evident in PLAN vessels. You can also add flares to your decoy system.

I just noticed this.

Regarding the canted nose seeker -- I do not think it is only using a ImIR seeker.

If it was only a ImIR seeker, they probably wouldn't have canted it in that manner, but they would've probably simply adopted a whole radome ImIR seeker like we've seen on some KD-88 variants before, such as below:

We also of course have the export variant of the canted nose YJ-83, dubbed CM-802B, that is described as having a "combined seeker".
To me, that suggests that the canted ImIR seeker is complemented by a radar seeker on the "top half" of the nose. Given the geometry of the upper half, I suspect the radar seeker is probably an entirely new array, perhaps even an AESA.

Either way I can't see the canted ImIR seeker being ImIR only -- because if the entire missile only has a ImIR seeker, there's no need to really cant it down in a way that only occupies the bottom half of the nose.

My personal hypothesis, is that the PLAN realized that a dual mode guidance (active radar and passive ImIR) would be necessary in the future. For the purposes of anti-ship missions, radar and ImIR offers the benefit of being able to detect and track your target in two mediums which makes defeating your seeker more difficult, as well as offering better performance in some environments (such as littorals, where ImIR is less affected by clutter).
A dual mode capability also means more in-built land attack capability for your AShM, because it means that the ImIR guidance can allow you to engage land targets more easily than a radar seeker can.

In pursuit of a dual mode guidance solution, they went for two routes, the first being adding a small side mounted ImIR seeker that can be installed to existing YJ-83 missiles without substantial modification (retaining the same existing radar seeker as well).

However, they also developed a clean build more capable YJ-83 variant which combines a larger and more integrated canted ImIR seeker, but which retains sufficient radome volume for a new, likely smaller and more capable radar seeker on the top half of the nose.
Frontal shots of the canted nose YJ-83 variant shows just how much free space there is on the top half of the nose, and I'm sure that space is being used for something.

Tam · Aug 8, 2022

Blitzo said:
I just noticed this.

Regarding the canted nose seeker -- I do not think it is only using a ImIR seeker.

If it was only a ImIR seeker, they probably wouldn't have canted it in that manner, but they would've probably simply adopted a whole radome ImIR seeker like we've seen on some KD-88 variants before, such as below:

We also of course have the export variant of the canted nose YJ-83, dubbed CM-802B, that is described as having a "combined seeker".
To me, that suggests that the canted ImIR seeker is complemented by a radar seeker on the "top half" of the nose. Given the geometry of the upper half, I suspect the radar seeker is probably an entirely new array, perhaps even an AESA.

Either way I can't see the canted ImIR seeker being ImIR only -- because if the entire missile only has a ImIR seeker, there's no need to really cant it down in a way that only occupies the bottom half of the nose.

My personal hypothesis, is that the PLAN realized that a dual mode guidance (active radar and passive ImIR) would be necessary in the future. For the purposes of anti-ship missions, radar and ImIR offers the benefit of being able to detect and track your target in two mediums which makes defeating your seeker more difficult, as well as offering better performance in some environments (such as littorals, where ImIR is less affected by clutter).
A dual mode capability also means more in-built land attack capability for your AShM, because it means that the ImIR guidance can allow you to engage land targets more easily than a radar seeker can.

In pursuit of a dual mode guidance solution, they went for two routes, the first being adding a small side mounted ImIR seeker that can be installed to existing YJ-83 missiles without substantial modification (retaining the same existing radar seeker as well).

However, they also developed a clean build more capable YJ-83 variant which combines a larger and more integrated canted ImIR seeker, but which retains sufficient radome volume for a new, likely smaller and more capable radar seeker on the top half of the nose.
Frontal shots of the canted nose YJ-83 variant shows just how much free space there is on the top half of the nose, and I'm sure that space is being used for something.

Fitting a radar seeker in a canted cone along with the canted IIR array looks way too tight. It greatly sacrifices the radar seeker with a much smaller array size, which has huge negative consequence on its transmission and receive gain, and the IIR seeker gets in the way of the radar seeker's lower FOV, again, negating its effectiveness for target searching and homing.

As for the earlier KD-88 variant, that's for the earlier versions, it does not mean that its optimal, given that its an early or first version. Pointing the array to the front might not make it as efficient for ground attack duties, since you would need to pivot the array downwards at an angle against ground targets. That would induce some distortion with the flat glass and you would have to add weight and complexity by adding a pivoting mechanism behind the infrared pixel array.

The canted version is the second and improved version of that idea. You remove the distortion of the glass window and you already placed the array in an optimal position. Given that IIR is a bit more complex than infrared homing, the rest of the dome can be dedicated to the supporting electronics. You want to leave as much space for the rest of the missile behind the dome for the batteries, the bigger your batteries are, the longer the missile can operate before it dies running out of juice. In fact battery life is as important to missile range as the fuel and engine efficiency, the longer the battery life, the longer the missile can operate, and therefore, the longer the missile's range and reach.

If the missile has 300km+ ranges, this suggests the missile frame has ample battery reserves so this means you want to put the complex electronics used to process infrared pixels right at the nose dome.

Blitzo · Aug 8, 2022

Tam said:
Fitting a radar seeker in a canted cone along with the canted IIR array looks way too tight. It greatly sacrifices the radar seeker with a much smaller array size, which has huge negative consequence on its transmission and receive gain, and the IIR seeker gets in the way of the radar seeker's lower FOV, again, negating its effectiveness for target searching and homing.

As for the earlier KD-88 variant, that's for the earlier versions, it does not mean that its optimal, given that its an early or first version. Pointing the array to the front might not make it as efficient for ground attack duties, since you would need to pivot the array downwards at an angle against ground targets. That would induce some distortion with the flat glass and you would have to add weight and complexity by adding a pivoting mechanism behind the infrared pixel array.

The canted version is the second and improved version of that idea. You remove the distortion of the glass window and you already placed the array in an optimal position. Given that IIR is a bit more complex than infrared homing, the rest of the dome can be dedicated to the supporting electronics. You want to leave as much space for the rest of the missile behind the dome for the batteries, the bigger your batteries are, the longer the missile can operate before it dies running out of juice. In fact battery life is as important to missile range as the fuel and engine efficiency, the longer the battery life, the longer the missile can operate, and therefore, the longer the missile's range and reach.

If the missile has 300km+ ranges, this suggests the missile frame has ample battery reserves so this means you want to put the complex electronics used to process infrared pixels right at the nose dome.

I looks fine to me, if they put an AESA in there it could be very appropriate to the size available to it.

More importantly, the plaque for the CM-802B directly states it has a "combined seeker," so I strongly doubt that the seeker head only contains ImIR.

Dual mode seekers on the heads of missiles is really the norm for where things are headed -- see the Israeli Stunner/David's sling for a ARH+ImIR BVRAAM.
Utilizing such a guidance method for a AShM seems like a very reasonable application of dual mode guidance, and I expect that in the future dual mode -- or even trimode -- seekers will become the new baseline standard.

Tam · Aug 8, 2022

Blitzo said:
I looks fine to me, if they put an AESA in there it could be very appropriate to the size available to it.

More importantly, the plaque for the CM-802B directly states it has a "combined seeker," so I strongly doubt that the seeker head only contains ImIR.

Dual mode seekers on the heads of missiles is really the norm for where things are headed -- see the Israeli Stunner/David's sling for a ARH+ImIR BVRAAM.
Utilizing such a guidance method for a AShM seems like a very reasonable application of dual mode guidance, and I expect that in the future dual mode -- or even trimode -- seekers will become the new baseline standard.

AESA is not immune from the laws of physics. The smaller the receptive area, the weaker the receive gain and the poorer your angular resolution is. Doesn't matter what kind of array it is. Besides with the IIR occupying the lower half of the dome, how can the radar array point downwards to lock in on a surface target? That is why in the other YJ-83 variant, the ARH seeker has access to the entire FOV of the dome and the IR seeker protrudes like a pimple underneath it.

As for combined seeker of the canted nose YJ variant, its likely the missile's "second seeker" is its own inertia, datalink updated and GPS-Beidou guided system. Meaning, the missile is already programmed with the target's GPS coordinates and the missile will fly and hit those coordinates even without using its IIR system. The GPS and Beidou will guide the missile, with occasional midphase updates. This kind of system is usually placed at the top part of the missile where you have a nice FOV of the sky for satellite line of sight which isn't going to contradict with the canted IIR system occupying the bottom half of the nose dome. Used in this mode, the IIR seeker will simply stream back an image of the target as the missile closes in to its destruction, allowing the observers to determine and confirm the kill.

Blitzo · Aug 8, 2022

Tam said:
AESA is not immune from the laws of physics. The smaller the receptive area, the weaker the receive gain and the poorer your angular resolution is. Doesn't matter what kind of array it is. Besides with the IIR occupying the lower half of the dome, how can the radar array point downwards to lock in on a surface target? That is why in the other YJ-83 variant, the ARH seeker has access to the entire FOV of the dome and the IR seeker protrudes like a pimple underneath it.

As for combined seeker of the canted nose YJ variant, its likely the missile's "second seeker" is its own inertia, datalink updated and GPS-Beidou guided system. Meaning, the missile is already programmed with the target's GPS coordinates and the missile will fly and hit those coordinates even without using its IIR system. The GPS and Beidou will guide the missile, with occasional midphase updates. This kind of system is usually placed at the top part of the missile where you have a nice FOV of the sky for satellite line of sight which isn't going to contradict with the canted IIR system occupying the bottom half of the nose dome.

I never said that AESAs are immune to physics, however it is absolutely reasonable to suggest that they could achieve effective performance for a AShM seeker inside a smaller cross section than the legacy radar seeker in older YJ-83 variants using older technology.

An AESA located in the top half of the nose would absolutely be able to have look down capability without needing to be placed on a mechanical gimbal. Heck, it could even be canted at an upwards angle like how some fighter aircraft have an upwards cant on their radome bulkheads, while still possessing excellent lookdown air to surface capability.

My overall point is that there's no particular technological reason why an effective AESA seeker could not be mounted in the top half of the nose.
That, combined with the establishment of a half-remedy dual mode ImIR+ARH guidance solution on existing missiles, and combined with the CM-802B placard directly stating the missile has a "combined seeker," leads me to believe the missile likely has a dual mode ImIR+ARH guidance solution.

If they were describing midcourse guidance, then it likely would have been described as "combined guidance".
"Seeker" directly suggests that it is talking about the missile's own organic seeker to search for and scan for targets.

Tam · Aug 8, 2022

Blitzo said:
I never said that AESAs are immune to physics, however it is absolutely reasonable to suggest that they could achieve effective performance for a AShM seeker inside a smaller cross section than the legacy radar seeker in older YJ-83 variants using older technology.

An AESA located in the top half of the nose would absolutely be able to have look down capability without needing to be placed on a mechanical gimbal. Heck, it could even be canted at an upwards angle like how some fighter aircraft have an upwards cant on their radome bulkheads, while still possessing excellent lookdown air to surface capability.

My overall point is that there's no particular technological reason why an effective AESA seeker could not be mounted in the top half of the nose.
That, combined with the establishment of a half-remedy dual mode ImIR+ARH guidance solution on existing missiles, and combined with the CM-802B placard directly stating the missile has a "combined seeker," leads me to believe the missile likely has a dual mode ImIR+ARH guidance solution.

If they were describing midcourse guidance, then it likely would have been described as "combined guidance".
"Seeker" directly suggests that it is talking about the missile's own organic seeker to search for and scan for targets.

I don't really know how the AESA canted that way would have look down capability. Remember that the reasonable angle for the AESA plane should be around 60 degrees. However, there is significant loss of transmission and receive gain when you reach there.

A gimbal would have added to the missile's weight and complexity. Missiles needed to be as simple as possible to reduce weight, allow for more space to support its primary functions, and improve reliability. You need as much room for the back end electronics and battery.

Your best bet is a chisel shaped structure with the lower angle occupied by the IIR array and the upper array occupied by the radar array. But again if you draw a 60 degree angle from the upper cant, you're going to see it has a problem looking downwards.

If you put the upper angle straight, you will have a much better FOV on the look down. However, the array size will be smaller compared to the length of the cant, as you have the smaller side of the triangle. Your ARH electronics will occupy the upper half with the IIR electronics on the bottom half.

If you assume that this will be AESA --- which has never been confirmed directly or publicly --- how is this going to be any better if we have AESA for the >>entire<< radome? You have a radar array at least twice the size with far more elements with greater space for gimbal movement. Instead of a half arsed rectangular or oval array, you have a full square or octagonal array for both fullvertical and horizontal scanning. Then slap an IR homing seeker underneath for a just in case situation? It could turn out, that the latter design may end up being superior.

Blitzo · Aug 8, 2022

Tam said:
I don't really know how the AESA canted that way would have look down capability. Remember that the reasonable angle for the AESA plane should be around 60 degrees. However, there is significant loss of transmission and receive gain when you reach there.

A gimbal would have added to the missile's weight and complexity. Missiles needed to be as simple as possible to reduce weight, allow for more space to support its primary functions, and improve reliability. You need as much room for the back end electronics and battery.

Your best bet is a chisel shaped structure with the lower angle occupied by the IIR array and the upper array occupied by the radar array. But again if you draw a 60 degree angle from the upper cant, you're going to see it has a problem looking downwards.

View attachment 95127

If you put the upper angle straight, you will have a much better FOV on the look down. However, the array size will be smaller compared to the length of the cant, as you have the smaller side of the triangle. Your ARH electronics will occupy the upper half with the IIR electronics on the bottom half.

If you assume that this will be AESA --- which has never been confirmed directly or publicly --- how is this going to be any better if we have AESA for the >>entire<< radome? You have a radar array at least twice the size with far more elements with greater space for gimbal movement. Instead of a half arsed rectangular or oval array, you have a full square or octagonal array for both fullvertical and horizontal scanning. Then slap an IR homing seeker underneath for a just in case situation? It could turn out, that the latter design may end up being superior.

The purpose of any sort of dual/combined mode guidance is to try and find the balance between having the best performance for each sensor type, for a given role for your missile or platform.

The way I am approaching this, is that the CM-802B placard seems to strongly suggest that the seeker itself is a combined seeker, which combined with the relatively small part of the radome that the ImIR aperture takes up, with the fact that we've seen a more haphazard dual mode ImIR+ARH guidance solution on older YJ-83 missiles, makes me speculate that it is very likely or at least reasonable to believe that the CM-802B/canted YJ-83 variant is also a dual mode missile.

Unless there is any sort of slam dunk technological explanation for why such a configuration is infeasible or illogical, then the best that can be said is "we need more information to confirm/deny". But as it is, I think the chances are not low that the canted YJ-83 variant has a dual mode seeker.

Tam · Aug 8, 2022

Blitzo said:
The purpose of any sort of dual/combined mode guidance is to try and find the balance between having the best performance for each sensor type, for a given role for your missile or platform.

The way I am approaching this, is that the CM-802B placard seems to strongly suggest that the seeker itself is a combined seeker, which combined with the relatively small part of the radome that the ImIR aperture takes up, with the fact that we've seen a more haphazard dual mode ImIR+ARH guidance solution on older YJ-83 missiles, makes me speculate that it is very likely or at least reasonable to believe that the CM-802B/canted YJ-83 variant is also a dual mode missile.

Unless there is any sort of slam dunk technological explanation for why such a configuration is infeasible or illogical, then the best that can be said is "we need more information to confirm/deny". But as it is, I think the chances are not low that the canted YJ-83 variant has a dual mode seeker.

There's a good slam dunk explanation already and that is a half radar seeker is no doubt absolutely inferior to a full one. Not just in transmit and receive gain, but also in angular resolution, full scanning of the vertical and the horizontal, and in the look down field of view. A full seeker allows a regular symmetrical octagonal instead of a half oval, this means the number of elements in vertical arrangement is equal to a horizontal one, unlike a half or oval seeker. You cannot say that the deficiency of being half a seeker can be solved with an AESA when there is even no written or official word that says this. And even if it's an AESA, it still makes no sense when you can have a full sized AESA seeker by applying the same level of technology.

As I explained to you, a GPS coordinate based guidance system is a guidance system nonetheless that can support an IIR system.

Lastly the dual ARH+IRH mode of supposedly older (I do not think they're older but in parallel) YJ-83 isn't by any means inferior. You have to explain how that is.

It's likely that both missiles exist simultaneously with different mission profiles. The canted missile nose type is for littoral ship engagement and against land surface targets. Littoral ship engagement favors IIR because shallow sea and beach radar reflection clutter gives seekers the fits. IIR also favors hitting land targets.

The dual ARH + IRH mode missile is more optimized for deep sea antiship engagement. Radar always trump IR in range, allowing you larger areas of search and longer ranges of lock in. The IRH is a back up counter to being radar jammed.

There is no indication that the pictures of the dual mode missile were taken before the canted one, and it seemed they were even posted later. This leans towards that both missiles are in simultaneous service but with different mission profiles.

I will add that an IIR land attack missile with GPS guidance should be cheaper to manufacture en masse and there's a huge benefit of having sheer numbers of cheap missiles to deal with land targets that are both numerous and cheap. This is the kind of missile that I would expect to be fired off not just from aircraft but land TELs placed all over the Fujian province facing Taiwan to hit various land targets in the island.

Blitzo · Aug 8, 2022

Tam said:
There's a good slam dunk explanation already and that is a half radar seeker is no doubt absolutely inferior to a full one. Not just in transmit and receive gain, but also in angular resolution, full scanning of the vertical and the horizontal, and in the look down field of view. A full seeker allows a regular symmetrical octagonal instead of a half oval, this means the number of elements in vertical arrangement is equal to a horizontal one, unlike a half or oval seeker. You cannot say that the deficiency of being half a seeker can be solved with an AESA when there is even no written or official word that says this. And even if it's an AESA, it still makes no sense when you can have a full sized AESA seeker.

We are not comparing a half nose radar seeker to a full radar seeker.

We are comparing a contemporary half nose radar seeker on the current production canted nose ImIR variant YJ-83 with the full nose radar seeker on the older production YJ-83, and whether the performance on a half nose radar seeker is sufficient for the mission it needs.

Obviously the performance of a half nose radar seeker will be inferior to a full nose radar seeker.
But that is irrelevant to the discussion.

All that matters is whether a contemporary, current production half nose radar seeker with current technologies is sufficient for its given mission.

Tam said:
As I explained to you, a GPS coordinate based guidance system is a guidance system nonetheless that can support an IIR system.

I never said that GPS/satellite guidance is unable to support ImIR guidance.
I literally never disputed this point at all.

Tam said:
Lastly the dual ARH+IRH mode of supposedly older (I do not think they're older but in parallel) YJ-83 isn't by any means inferior. You have to explain how that is.

It's likely that both missiles exist simultaneously with different mission profiles. The canted missile nose type is for littoral ship engagement and against land surface targets. Littoral ship engagement favors IIR because shallow sea and beach radar reflection clutter gives seekers the fits. IIR also favors hitting land targets.

The dual ARH + IRH mode missile is more optimized for deep sea antiship engagement. Radar always trump IR in range, allowing you larger areas of search and longer ranges of lock in. The IRH is a back up counter to being radar jammed.

There is no indication that the pictures of the dual mode missile were taken before the canted one, and it seemed they were even posted later. This leans towards that both missiles are in simultaneous service but with different mission profiles.

I will add that an IIR land attack missile with GPS guidance should be cheaper to manufacture en masse and there's a huge benefit of having sheer numbers of cheap missiles to deal with land targets that are both numerous and cheap.

Well, I respectfully disagree.

I think the CM-802B placard is rather specific in its description of a combination seeker.
Intuitively, the pursuit of a more refined and more modern dual mode ImIR+ARH guidance system makes a lot of sense, and this particular missile looks to fit the bill perfectly reasonable as well.

Tam · Aug 8, 2022

Blitzo said:
We are not comparing a half nose radar seeker to a full radar seeker.

We are comparing a contemporary half nose radar seeker on the current production canted nose ImIR variant YJ-83 with the full nose radar seeker on the older production YJ-83, and whether the performance on a half nose radar seeker is sufficient for the mission it needs.

Obviously the performance of a half nose radar seeker will be inferior to a full nose radar seeker.
But that is irrelevant to the discussion.

All that matters is whether a contemporary, current production half nose radar seeker with current technologies is sufficient for its given mission.

I never said that GPS/satellite guidance is unable to support ImIR guidance.
I literally never disputed this point at all.

Well, I respectfully disagree.

I think the CM-802B placard is rather specific in its description of a combination seeker.
Intuitively, the pursuit of a more refined and more modern dual mode ImIR+ARH guidance system makes a lot of sense, and this particular missile looks to fit the bill perfectly reasonable as well.

You think that comparing a half seeker to a full one is irrelevant but it is completely and absolutely relevant. The array size and number of elements is absolutely important to its performance. Being sufficient is not enough. Military procurement means you also have to judge across a wide range of similar proposals using alternative means and select which provides the superior performance. Not because it's 'enough'.

CM-802B placard never mentioned an ARH seeker. Period. I remember FD2000 placards mention a composite guidance system and it turns out it's ARH + command guidance in midphase. Not some dual seeker head.

IIR guidance is best used against land targets, and AESA is too much of a cost to be wasted on a building when you can do it without the radar.

PLAN Anti-ship/surface missiles

Blitzo

Lieutenant General

Tam

Brigadier

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Brigadier

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Brigadier

Blitzo

Lieutenant General

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Blitzo

Lieutenant General

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Brigadier