054B/new generation frigate

AndrewS

Brigadier
Registered Member
This is just false. A fixed phased array radar with 4 faces does not scan the sky instantly. The SPY-1 radar on the Arleigh Burke’s that I compared against can radiate only from one radar face at a time. The upgraded versions are able to radiate from two faces simultaneously, but never from all four.

PESA/AESA radars with electronic scans still require non trivial time to perform a scan: this will be a function of beam width and dwell time. Dwell time will be a function of radar performance characteristics.

I think there isn't that much practical difference for volume search between 4 fixed panels and 1 rotating panel.

However, in terms of damage resilience, even minor damage to the rotation mechanism will result in a mission kill.

In comparison, minor damage to part of a fixed panel means the rest of the panel can still operate.

And in a high intensity conflict, there will certainly be battle damage

Plus you have the other 3 AESA panel faces separately located on the rest of the superstructure.

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Something similar applies to the Sampson rotating fire-control X-Band radar at the top of the Type-45 mast versus say the 4 fixed X-Band panels at the top of the Type-055 mast.

But in addition, what happens when there is a coordinated multi-vector attack? The rotating nature of the Sampson imposes critical update delays

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Plus from a doctrinal perspective, the British Navy can't rely on AWACs so would benefit from a higher placed radar. In comparison, both the US Navy and Chinese Navy can expect AWACs to provide over the horizon radar coverage.

It also helps that rotating radars are cheaper, as the British military has been operating on shoestring budgets for decades now.

Note that the lack of British carrier AWACs was a budgetary decision.
 
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Lethe

Captain
That is a sweeping statement against physics. Fixed phased array radar (PESA or AESA) scans the sky electronically, that is instant. A one faced AESA on type 45 sweeps the sky as fast as its motor can rotate. Being a mechanically rotating AESA is still much slower than an old 4 faced PESA on AB ships to sweep the 360 degrees around you.

054B's two faced AESA doubles the sweeping speed at the same rotating speed which is better than type 45, but still behind 052C/D.

Type 45 can mount its radar higher because it has only one small panel and lighter. It is an advantage but has its disadvantage at the same time. Type 45 being a dedicated air defence ship is because that is the best UK can get, not because it is best technical solution compared with others.

The SAMPSON radar fitted to Type 45 has two radiating faces like 054B's radar. The related EMPAR radar used on French and Italian Horizon-class destroyers is single-face. The UK's desire for increased radar capability is one of the factors that led the nation to split from the Horizon program.

It should also be noted that SAMPSON's performance is supplemented by the S1850M L-band radar for volume search.
 

snake65

Junior Member
VIP Professional
European APAR and Israeli MF-STAR are fixed face top-mast placed radars. There is a trade-off between volume and power or radio horizon for low-path fast targets, therefore a second radar for volume search is added, although UK has claimed that in case of Sampson it's redundant. Russians have gone for third solution - top-mast S-band volume search and fixed face X-band in the mast below.
 

Tam

Brigadier
Registered Member
I think there isn't that much practical difference for volume search between 4 fixed panels and 1 rotating panel.

However, in terms of damage resilience, even minor damage to the rotation mechanism will result in a mission kill.

In comparison, minor damage to part of a fixed panel means the rest of the panel can still operate.

And in a high intensity conflict, there will certainly be battle damage

Plus you have the other 3 AESA panel faces separately located on the rest of the superstructure.

---

Something similar applies to the Sampson rotating fire-control X-Band radar at the top of the Type-45 mast versus say the 4 fixed X-Band panels at the top of the Type-055 mast.

But in addition, what happens when there is a coordinated multi-vector attack? The rotating nature of the Sampson imposes critical update delays

---

Plus from a doctrinal perspective, the British Navy can't rely on AWACs so would benefit from a higher placed radar. In comparison, both the US Navy and Chinese Navy can expect AWACs to provide over the horizon radar coverage.

It also helps that rotating radars are cheaper, as the British military has been operating on shoestring budgets for decades now.

Note that the lack of British carrier AWACs was a budgetary decision.


SAMPSON radar is an S-Band not an X. The Type 45 does not have any X-band air defense radars like the Type 055. The Type 45 has the SAMPSON S-Band radar on top of the mast and the S1850 (Thales) L-band radar.

The Type 055 had has four S-Band fixed radars on the superstructure and four X-Band radars on the top mast.

The L-Band on the Type 45 gives terrific range and better anti stealth detection. However L-band isn't very good against small diameter objects flying very low over the water where it's prone to sea clutter. That's your typical sea skimming missile. Even S-Band has problems with sea clutter.

To deal with sea clutter, you need higher frequency radars that give better resolution. Water doesn't reflect back higher radar frequencies, they tend to absorb it instead so it doesn't reflect back as clutter.

However having both S and X band search radars on the same ship adds to its cost. The USN is acutely aware of the sea skimmer problem by adding the X-Band SPQ-9B radar onto AEGIS destroyers as an upgrade. The Zumwalt was originally planned to have both S and X band AESA radars for this reason. But budgeting issues meant canceling the S-Band radars and leaving the X-Band radars instead. That alone tells you that defending low flyers has become a bigger issue than dealing high altitude bombers at range.

The PLAN is aware of this issue having developed the C-band Type 364 radar for this. The Russians in turn developed the X-Band Pozitiv-M radar which actually ended up in the last two Sovremenny sold to the PLAN and incorporated on the Admiral Grigorovich frigates.

IMO, the X-Band Thales APAR, like used on the Sachsen class frigates is a better idea and a much more direct comparison to the Type 055's top mast X-Band radars. That's more clutter proof and a better fit against low flying sea skimmers.

Going to the Japanese Navy, the Akizuki and Asahi class of destroyers rely on a combination of C and X band, and the Mogami frigates use X-Band exclusively. So there's the trend going for the higher bands.

The 054B relies on a combination of S and X band radars, the X band radar is another dual faced phase array rotating under a dome beneath the ESM array.
 

AndrewS

Brigadier
Registered Member
SAMPSON radar is an S-Band not an X. The Type 45 does not have any X-band air defense radars like the Type 055. The Type 45 has the SAMPSON S-Band radar on top of the mast and the S1850 (Thales) L-band radar.

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

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

However having both S and X band search radars on the same ship adds to its cost. The USN is acutely aware of the sea skimmer problem by adding the X-Band SPQ-9B radar onto AEGIS destroyers as an upgrade.

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

It's costing the US about $4 Mn for each upgrade, so it does look like it is worth doing, considering the increasing number of sea-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?
 

antiterror13

Brigadier
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

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



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

It's costing the US about $4 Mn for each upgrade, so it does look like it is worth doing, considering the increasing number of sea-skimming missiles.

---

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?

I thought 052D had X-Band, it doesn't make sense for 052D to not having X-band while 054B has
 

AndrewS

Brigadier
Registered Member
I thought 052D had X-Band, it doesn't make sense for 052D to not having X-band while 054B has

@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?
 

taxiya

Brigadier
Registered Member
This is just false. A fixed phased array radar with 4 faces does not scan the sky instantly. The SPY-1 radar on the Arleigh Burke’s that I compared against can radiate only from one radar face at a time. The upgraded versions are able to radiate from two faces simultaneously, but never from all four.
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.
PESA/AESA radars with electronic scans still require non trivial time to perform a scan: this will be a function of beam width and dwell time. Dwell time will be a function of radar performance characteristics.
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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taxiya

Brigadier
Registered Member
The SAMPSON radar fitted to Type 45 has two radiating faces like 054B's radar. The related EMPAR radar used on French and Italian Horizon-class destroyers is single-face. The UK's desire for increased radar capability is one of the factors that led the nation to split from the Horizon program.

It should also be noted that SAMPSON's performance is supplemented by the S1850M L-band radar for volume search.
The subject was comparing volume search speed of SPY-1 with type 45. So the counterpart is S1850M.
 
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