054B/next generation frigate

AndrewS said:

If the Type-45 doesn't have an X-band AESA radar, that's even worse from the perspective of providing area air defence eg.

1. Detecting sea-skimming missiles from sea clutter
2. Discriminating against clusters of real missiles or decoy/jamming signals
3. Also detecting small boats

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Yes it's problem.

And it looks like every other air-defence ship type has an X-Band radars for fire control?

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Fire control and surface search are two different applications. Many if not most ships have an X-band for fire control, which is used for surface targeting with guns and antiship missiles in direct line of sight, some even capable of terminal missile illumination like the Thales STIR. One can say this architecture is ubiquitous enough to be near standard. PLAN ships also have such radars for gunnery and antiship use as standard fitting, even the 054B.

However an FC radar is meant to track a target by continuously staring it keeping the beam on target to produce a fire quality track. It lacks 360 circular coverage that provides situational awareness. That's what a search radar does.

The PLAN ship gives a good study of this architecture as you can see separate surface search Type 364 radar and have separate fire control radars, which are the Type 366, 344 and 347 or 349.

Presumably the existing Type-052D mast (with the Type-364 at the top) could be replaced with an X-Band SPQ-9B equivalent radar?

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Type 364 works well enough and PLAN seems satisfied with it. It's likely been internally improved over the years. The radar appears to be working on the higher range of the C-Band.

It's costing the US about $4 Mn for each upgrade, so it does look like it is worth doing, considering the increasing number osihtf s and antiship ea-skimming missiles.
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And if I look at the Sampson and SPQ-9B, they both weigh about 700kg.
Presumably the new dual-face X-Band AESA on the top of the Type-054B is a similar weight?

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Could be higher weight due to the double face, plus it might be bigger. Same radar is used on the latest 052D batch which some refer to as 052DG which I will use to refer to it. Externally the mast looks unchanged on the 052DG but it can have unseen internal modifications such as for cooling and wiring.

In theory if an existing 052D should upgrade to this radar, the current mast might be removed as a set. The new mast with the new radar would be installed as a complete set. Think of the ship as built from modular pieces. Should add again, this is in theory.

This same radar is used on the Type 075 and I already mentioned years ago it's going to appear on new ships as the Type 364 replacement.

Time will tell if older 054A and 052C/D will be upgraded to it but the PLAN seems addicted to building new ships from scratch to replace older ones which are relegated to secondary duties as a reserve.

AndrewS said:

@Tam

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I think the Type-052D does has X-band radars, with two X-band fire-control (target illumination) radars.
And that these are roughly equivalent to the ones on the Arleigh Burke Flight II.

But that these radars are single function, and don't have a surface search or air volume search modes?

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X-Band for gunnery and antiship control, but not for target illumination. The ships have the Type 366 for antiship and Type 344 for gunnery. These are situated above the bridge.

The 052D does not use target illumination radars because the missiles are active guided meaning they have self contained illumination. Even the 052C uses active guided missiles. This isn't Burke or AEGIS FC architecture, it's straight out directly comparable to the Type 45 with SAMPSON and it's Aster missiles. Except the missiles are S-300 sized. Don't let the appearance of the fixed radars fool you. These ships doesn't work like AEGIS.

The 054B does not appear to have illuminators either which point to using only the new HHQ-16F with active guidance. It will not use legacy HHQ-16 from older ships.

Both ships however do control the missiles directly via data link for their main flight phase. The data link should be embedded in the main radar array face itself. Not a new tech, as ground SAM radars feature this including the ground HQ-9.

AndrewS said:

@Tam

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I think the Type-052D does has X-band radars, with two X-band fire-control (target illumination) radars.
And that these are roughly equivalent to the ones on the Arleigh Burke Flight II.

But that these radars are single function, and don't have a surface search or air volume search modes?

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X-Band for gunnery and antiship control, but not for target illumination. The ships have the Type 366 for antiship and Type 344 for gunnery. These are situated above the bridge.

The 052D does not use target illumination radars because the missiles are active guided meaning they have self contained illumination. Even the 052C uses active guided missiles. This isn't Burke or AEGIS FC architecture, it's straight out directly comparable to the Type 45 with SAMPSON and it's Aster missiles. Except the missiles are S-300 sized. Don't let the appearance of the fixed radars fool you. These ships doesn't work like AEGIS.

The 054B does not appear to have illuminators either which point to using only the new HHQ-16F with active guidance. It will not use legacy HHQ-16 from older ships.

Both ships however do control the missiles directly via data link for their main flight phase. The data link should be embedded in the main radar array face itself. Not a new tech, as ground SAM radars feature this including the ground HQ-9.

taxiya said:

One beam or not does not change the fact that it is shared among four panels electronically, instead of 4 beams scanning 90 degrees, it is one beam scanning 360 degrees electronically compared to type 45's mechanically.

Define what is trivial time? You are telling me that an electric motor rotates tonnes of mass hundreds times per second not only match but surpass electric circuit in speed of sweeping 360 degrees?

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You are mistaking the time to steer the beam with the time to scan which are not the same thing. A radar, being a sensor working in EM spectrum, needs exposure time to detect things. Dwell time, which can be elongated by either longer pulses or more pulses sent to the same bearing, is directly related to signal-to-noise ratio of the return which enables detection.


If you assume perfect integration and a set pulse length this is the radar equation you get. n is the number of pulses. More pulses increase the range. Another thing here is Pav which is average power. Average power is calculated by multiplying peak power with duty cycle. For example if a radar has a duty cycle of 0.2 (kinda typical in solid state radars) and a peak power of 10 kW it will have an average power of 2 kW. If the pulse length here is 1 ms it means the radar will have a pulse repetition frequency of 200 Hz which appear as fp in the equation. At this point, the number of pulses determine how long the radar stays on the bearing. n = 20 would mean a dwell time of 0.1 seconds. Such a long dwell time, depending on your scanning pattern and beamwidth, can mean a very long scanning time. For example, the AN/TPY-2, which is an AESA, scans so slow that it can't be used for terminal engagements in one of its modes. That is how it achieves its massive range (~3000 km) against ballistic missiles. We are talking about minutes to scan a small portion of the sky here.

Summary: Electronic scanning doesn't mean instant scanning. Scanning a volume still takes the same time if you want to detect anything. Electronic scanning just means that the radar can jump between different sections of the sky instantly, which helps a lot with tracking multiple objects with a high refresh rate and without compromising search. A mechanical scanning radar can't track things unless it is scanning the sector the object is in or without deviating from the scanning pattern. And remember, visiting the object and returning back to scan takes time for the mechanical scanner.

To complement the excellent reply by @BoraTas, the Sampson radar on the Type 45 is a dual faced AESA. It can scan in elevation and azimuth at least 60 degrees off bore, thereby minimizing the update gaps in target tracks. Off course, phased array radars perform worse the more off bore the beam is. However this can also be an advantage of mechanically rotated arrays as they can always radiate the target at the optimal angle in azimuth.

Because long range volume search is an immensely time consuming task, the Sampson radar is complemented with the S1850M long range radar, also an AESA radar. The fact that both are AESAs means that the rotation of the array can be stopped allowing the radar to scan a fixed part of the sky: this is what the SMART-L radar does when performing an anti-ballistic missile detection and tracking role.

Tam said:

Type 364 works well enough and PLAN seems satisfied with it. It's likely been internally improved over the years. The radar appears to be working on the higher range of the C-Band.

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Given that the Type-052DG has replaced the Type-364 with a rotating dual-face X-Band, that would imply the Type-364 is no longer satisfactory.

Tam said:

In theory if an existing 052D should upgrade to this radar, the current mast might be removed as a set. The new mast with the new radar would be installed as a complete set. Think of the ship as built from modular pieces. Should add again, this is in theory.

This same radar is used on the Type 075 and I already mentioned years ago it's going to appear on new ships as the Type 364 replacement.

Time will tell if older 054A and 052C/D will be upgraded to it but the PLAN seems addicted to building new ships from scratch to replace older ones which are relegated to secondary duties as a reserve.

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Upgrading the existing 054A and 052C/D with a rotating dual-face X-Band (Cost $4Mn?) just seems like a significant increase in air defence capability for a very low cost, especially compared to the overall ship cost.

I can see the 054A being left as-is, as they should be operating under friendly air cover in an escort role or in conjunction with more capable destroyers.

But the same doesn't apply to the 052D, which is primarily an air-defence destroyer and would be expected to operate in high-risk areas.

@taxiya
The reason why the Sampson radar is superior to the SPY-1 is mostly due to its more advanced radar architecture and technology: it is a dual faced AESA S-band radar. It electronically steers its beam in both azimuth and elevation, unlike say a frequency scanned mechanically rotated radar that only electronically scans in elevation. This means that the radar can continue to track a target even when it is off-bore, minimising the time gap between successive updates. As the SPY-1 radar can only radiate from 1 or 2 faces simultaneously it has no functional advantage over the 2-faced Sampson radar in that aspect. Furthermore, the Sampson radar on the Type 45 is complemented with the S-1850M L-band AESA radar which performs the long range volume search function, allowing the Sampson radar to focus on horizon and medium range volume search. By virtue of its long wavelength and its large array (twice the size of SPY-1 at 8.4 x 4.4m), the S-1850M radar easily outperforms the SPY-1 in detection of VLO targets. When we add to this the AESA radar's superior performance against radar jamming, it is beyond any doubt that the Type 45 is a formidable air defense ship, in most aspects superior to the legacy Arleigh Burke destroyers. The FLIII Arleigh Burke, with the SPY-6 fully digital state-of-the-art AESA are obviously superior, but not the subject of the original comparison.

@Tam
Regarding your comment that X-band radars are preferred for horizon search because of their superior clutter performance.

As far as I am aware, X-band radars are preferred in horizon search because of their superior multi-path interference performance, compared to lower frequency radars. Because of multi-path interference, the elevation coverage ends up broken up into interference lobes: this both increases the detection range at the peaks of the lobes and vastly decreases it at the nulls. The lobe density increases with radar frequency, which is why X-band becomes preferable. Furthermore, X-band provides narrower beam width for equal antenna size and wider bandwidth which allows for superior target discrimination. Take a look at the picture below. The reflection coefficient in calm waters will be close to 1.

AndrewS said:

Given that the Type-052DG has replaced the Type-364 with a rotating dual-face X-Band, that would imply the Type-364 is no longer satisfactory.




Upgrading the existing 054A and 052C/D with a rotating dual-face X-Band (Cost $4Mn?) just seems like a significant increase in air defence capability for a very low cost, especially compared to the overall ship cost.

I can see the 054A being left as-is, as they should be operating under friendly air cover in an escort role or in conjunction with more capable destroyers.

But the same doesn't apply to the 052D, which is primarily an air-defence destroyer and would be expected to operate in high-risk areas.

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You can't compare the cost of the SPQ-9B radar to the dual faced AESA 'Type 368'. The SPQ-9B appears to be a PESA, indicated by its use of Yttrium, a rare earth metal that's been red flagged as one of those elements that turn out that China has a near monopolistic dominance of. Yttrium is used with ferrite phase shifters used in PESA, such as SPY-1. Type 368 on the other hand is likely a Gallium Nitride radar but then again even if GaN has become a commodity overflowing in China like in these days, the cost of the material is still only a tiny fraction of the system given the complexity and R&D of the final product.

The actual decision of executing an MLU for the 052C/D resides with the PLAN and it's bean counters. I don't have the sixth sense to read their minds if they will or will not. They're going to do all both the accounting and technical math and come to a decision which to my mind will be utterly rational.

As for now I have yet to see a vessel equipped with the Type 364 upgraded to the Type 368. A case in point was the Type 052B refits. They could have upgraded the contract to completely replace the Type 364 anyway, which by the way would have been the oldest working examples in the PLAN as these were the ships that first introduced the radar. But instead, they simply replaced it with the latest version of the Type 364. The old original radars would have been mechanically worn out at this point and may not be worth giving it an overhaul compared to a shiny new replacement. For that matter, the old Fregat ME search radars bought from the Russians used on this ship was replaced by a brand new Chinese indigenous Type 382 Sea Eagle, instead of the dual faced AESA as you see on the 054B. The Russian Front Domes were replaced with Chinese equivalents used on older 054A, but not the AESA illuminators from the last batch of 054A.

All this point to me that AESA isn't an easy plugin replacement to a legacy radar and there are other unseen under the hood nuances such as power supply and liquid cooling supply. That installing it on a new ship meant for it is easier than replacing a pre-installation.

A simple theory especially for the Type 054A is that the older ships may not have enough juice for it, and may require an overhaul of the electrical systems and power generation. The newer ships on the other hand, were designed with it on the blueprints with this consideration.

Another point to make is that these dual faced arrays appear to be liquid cooled with no evidence of any air cooling of any kind. That means the liquid cooling has to be routed through the rotary coupler at the base of the radar and the heat exchanger needs to be somewhere in the mast or beneath the mast with the coolant plumbing heading up and down the mast. On the oil mechanical radar, such plumbing would not exist. This is why I suggested that it would be the entire legacy mast structure that will be replaced with a new mast module that contains all the requisite plumbing, rotary coupler and beefed up electrical cabling.

Finally the heat exchanger itself needs to route the heated air to somewhere it won't be thermally detected with sensors perhaps through the chimneys.

banjex said:

Is this a radar thread now?

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Not as much as what's needed to explain the causes and evolution of the radar and sensor architecture, design, along with the overall doctrine or philosophy that defines these ships. The sensor makeup is a huge part of a modern warship.

Zichan said:

To complement the excellent reply by @BoraTas, the Sampson radar on the Type 45 is a dual faced AESA. It can scan in elevation and azimuth at least 60 degrees off bore, thereby minimizing the update gaps in target tracks. Off course, phased array radars perform worse the more off bore the beam is. However this can also be an advantage of mechanically rotated arrays as they can always radiate the target at the optimal angle in azimuth.

Because long range volume search is an immensely time consuming task, the Sampson radar is complemented with the S1850M long range radar, also an AESA radar. The fact that both are AESAs means that the rotation of the array can be stopped allowing the radar to scan a fixed part of the sky: this is what the SMART-L radar does when performing an anti-ballistic missile detection and tracking role.

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PESAs and AESAs can also do things like adopting specialized scanning patterns and pulse parameters once a contact is detected depending on the situation. They can use a different PRF and scanning pattern for tracking the detected objects while continuing to search normally, for example. Instant beam steering help with this a lot especially if a high number of objects are being tracked. If something is close they can start to use more resolution orinted parameters or decrease the resources commited on that track (less powerful pulses, less time allocated at each refresh, etc...), or a combination of both.

We know that the S1850M on the Daring can do tracking too. L-Band is not that appropriate for engagements but the said radar is a large AESA radar and the Aster series are active-radar guided munitions. Especially within 200 km of the ship, it should have no problems with guiding missiles. So as you said, the Type 45 kinda has a 4 faced AESA solution. If it faced a three vector attack that the SAMPSON can't track continuously or get overwhelmed, the S1850M too can be used for engagement. The S1850M would adopt resolution oriented parameters while contributing to the engagement. The Aster doesn't need a continuous or very high quality track either.

Is this a radar thread now?

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No. But radars are so central to warship performance that they deserve a lot of discussion. Also, examples of other solutions are useful to discuss radars. Especially since we don't have access to specific data.