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Re: JMSDF Akizuki Class DDG (19DD AEGIS-like)

Jeff Head said:

You just can't help yourself and seemingly must always give into the urge to put some anal-retentive comment into your reply, don't you? That never helps with dialog or reasoned discussion.

I never said the X-band would be as good as the S-Band,. Neither has the US Navy. Go back and read what I did say instead of responding to something I did not say.

What has been said is that as a stop gap they have modified the MFR to allow for volume search functionality.

There are clearly trade-offs for such a stop-gap in range, and, equally importantly, in impacting the MFR's other functions while performing any volume search.

But, it is a stop gap, and those will be trade offs they live with unless and until the S-and is completed and put into the vessels, or until such time as the adopt the AMDR later..

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It is a "stop gap" that's more than likely permanent. First, for a class of only three vessels, expensive upgrade program for such small number is highly unlikely in this budget environment. Second, Zumwalt mission profile, a steathy strike ship, doesn't require expensive and heavy VSR. a big radiating radar negates the benefits of the stealthy hull (stealthy at the expense of stability btw). Third, the switch to steel structure is final, contract signed.
The implication is that there is going to be more top weight on a ALREADY UNSTABLE hull. There is not going margin for growth. The 2 Zumwalts with composite superstructure may be able to take the additional weight of radar upgrade. But how likely is initiate an upgrade program for only 2 vessels? and you get incompatibility in an already tiny class of 3. The navy's decision to go with steel is a signal that there is no plan to retrofit VSR.

Re: JMSDF Akizuki Class DDG (19DD AEGIS-like)

shen said:

It is a "stop gap" that's more than likely permanent. First, for a class of only three vessels, expensive upgrade program for such small number is highly unlikely in this budget environment

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Perhaps so in the current environment, but "this" environment will not last forever, and the planners know this, hence the space remaining available. The number of vessels will not negate the likelihood at all that such upgrades will be visited. Look at the huge amount of money spent on "upgrading" a single vessel of the three boat Sea Wolf class. Look at the huge amounts of money that were spent on modernizing the four ship Iowa class. There are a lot of these types of examples. If the class is viewed as important enough, they will get the upgrades, and I can promise you the Zumwalts are going to be viewed as extremely important. For example, I expect all three will get the rail gun upgrade as soon as they are available.

shen said:

Second, Zumwalt mission profile, a steathy strike ship, doesn't require expensive and heavy VSR. a big radiating radar negates the benefits of the stealthy hull (stealthy at the expense of stability btw).

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Au Contraire. It's mission profile to provide a full slate of multi-role finctions in the littorals where its stealth allows it to surprise opposing forces, will actually require something like it be available so it can defend itself as well as possible once it engages, hence the upgraded MFR, and the space reservation for the VSR.

shen said:

Third, the switch to steel structure is final, contract signed.

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Thanks for the link regarding the final disposition for the deck house for unit number three. I believe it is unfortunate...but they are also planning to keep the space available for the volume search should it be revisited.

shen said:

The implication is that there is going to be more top weight on a ALREADY UNSTABLE hull. There is not going margin for growth. The 2 Zumwalts with composite superstructure may be able to take the additional weight of radar upgrade. But how likely is initiate an upgrade program for only 2 vessels? and you get incompatibility in an already tiny class of 3. The navy's decision to go with steel is a signal that there is no plan to retrofit VSR.

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Actually not. The article itself indicates that this change is going to be effected without impacting other considerations and that the weight for the steel deck house would be made up elsewhere.

Time will tell if they get the Volume Search or not...or later the AMDR. But they are reserving the space for it.

We will just have to see in the future what happens with that.

Re: JMSDF Akizuki Class DDG (19DD AEGIS-like)

shen said:

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Weapon control radar should be higher to get maximum radar horizon against sea skimming missiles.
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Is this true for what's available on 19DD for the terminal guidance of ESSMs, which is the AESA X-band of the FCS-3A radar?! Note the AESA, which is an improvement over the AN/SPG-62 — Continuous Wave Illuminator used with AEGIS, isn't it? shen?

2 nice videos for fun

FORBIN said:

2 nice videos for fun

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Well, those two videos show a fictional confrontation with China and Japan over the Islands where in 15+ years the Chinese send a two carrier task force out to exert air control...taking out several Japanese F-15s in the process with J-15s from the carriers.

Then the Japanese respond in the air to air role with F-3As which they are supposed to fly as prototypes in the 2016-2017 time frame, and in the anti-shipping role with what they call F-3E aircraft which look suspiciously like the US Navy FXX design (tailess).

The result is the supression of the Chinese carrier escort defenses and the sinking of both Chinese carriers. At the end you see that at least some of the F-3s came from a Japanese carrier...which is clearly not just a STOVL carrier but looks to have traps...so STOBAR at least.


The other video at FORBIN's link is a shorter video showing some of the same, but the last shot of the Japanese carrier shows F-35Cs on what appears to be a JMSDF CATOBAR design.

Apparently all of this is a marketing campaign for some fictional book about such a confrontation. So, I do not believe ti can be construed as offical Japanese Defense/Government policy or strategy.

Jeff I am not sure about those being F35Bs the craft on the deck clearly have folded wings and the take of looked like CATBAR which indicate F35C. The F3Es remind of more of the concept then Boeings FAXX. Now I really doubt this as being related to the SDF more likely the books publisher got in touch with a graphics house. And those wanting propaganda are trying to make a connection. The island issue has already sold a million books in China, so it will sell another million in Japan and a few more million every where else.

Japan AAM-4B first air to air missile with AESA seeker


back in 1997 satory def. exh. french also show new anti ship missile with AESA seeker,but due to budget problem, the plan was abandone.and wondering if PL-15 also AESA seeker?

Re: JMSDF Akizuki Class DDG (19DD AEGIS-like)

Jeff Head said:

Thanks for the link regarding the final disposition for the deck house for unit number three. I believe it is unfortunate...but they are also planning to keep the space available for the volume search should it be revisited.

Actually not. The article itself indicates that this change is going to be effected without impacting other considerations and that the weight for the steel deck house would be made up elsewhere.

Time will tell if they get the Volume Search or not...or later the AMDR. But they are reserving the space for it.

We will just have to see in the future what happens with that.

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on your points about the budget and mission profile, we'll just have agree to disagree. on the final point about weight saving, well, what do you think is the biggest weight saving, the deletion of the VSR!

Re: JMSDF Akizuki Class DDG (19DD AEGIS-like)

Jura said:

Is this true for what's available on 19DD for the terminal guidance of ESSMs, which is the AESA X-band of the FCS-3A radar?! Note the AESA, which is an improvement over the AN/SPG-62 — Continuous Wave Illuminator used with AEGIS, isn't it? shen?

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not sure if I'm understanding your question correctly Jura. the X band part of the FCS-3A, with imported ICWI technology, is suppose to handle the terminal illumination of ESSM.
My point was that ideally, the the X band part of the radar shouldn't be on the same level as the C-band search radar. look at the two lower displacement European frigates I wrote about early, the X-band APAR radar is on the way on the top of the ship, while the SMART-L search radar in much lower. X-band radar has better resolution, ideal for detection small targets like sea skimming missile, so it should be as high as possible to gain maximum radar horizon. the longer band volume search radar doesn't need to very high since at long range most targets are near the horizon anyway, by place it lower, you can use large antenna to improve radar performance without compromising the stability of the ship.
now, the compromise adopted by the Japanese may be forgivable if they put FCS-3A on a 4000tonnes range cheap frigate. but the Akizuki is bigger, just as expensive and manpower intensive as the more capable European frigates. that is bad design.

Re: JMSDF Akizuki Class DDG (19DD AEGIS-like)

shen said:

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My point was that ideally, the the X band part of the radar shouldn't be on the same level as the C-band search radar.
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shen, or anybody, can you estimate what the difference would make placing the X-band antenna, say, 10 meters higher on a ship, with respect to the detection of a sea-skimming missile doing, say, 240 m/s? I of course assume the same radars and the trajectories of the same missiles and the answer would be, for example, "the detection at 25 instead of 20 kilometers"; if you don't want to post here, please email what you think to Krize1938_at sign_seznam.cz, thanks!