Aegis Combat System

Take command of air and naval assets from post-WW2 to the near future in tactical and operational scale, complete with historical and hypothetical scenarios and an integrated scenario editor.

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greycat
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Aegis Combat System

Post by greycat »

I'm playing the "Indian Ocean Brawl" user scenario and my US SAG has come under air/missile attack. The SAG includes an Aegis cruiser (Ticonderoga Baseline 3 VLS). If I understand the Aegis system correctly, the Standard missiles fly towards the target on auto-pilot (receiving mid-course corrections if necessary) and employ semi-active radar homing during the terminal phase. In other words, the missile is flying 'blind' most of the time, as the target is only illuminated at the last moment.

However, many of the missiles simply fly past the target without engaging. The message log shows "... cannot have its target illuminated" or "... is not receiving target updates from parent unit... going autonomous". It seems to me that the Aegis system in unable to handle the large number of missiles in the air, even though it should be able to. As a result, large numbers of valuable SAMs are being wasted. Can anyone enlighten me as to what may be happening?

Thanks in advance.
thewood1
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RE: Aegis Combat System

Post by thewood1 »

OK, I'll just look at the save...oh, wait, there isn't one.

Its helpful to everyone if you can post a save right at the point of the issue. It saves everyone some time.
greycat
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RE: Aegis Combat System

Post by greycat »

Oops,here it is...
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Primarchx
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RE: Aegis Combat System

Post by Primarchx »

Looks like their targets are below the radar horizon before the missiles can engage. Aircraft tend to dive for the deck when targetted by SAMs in Command.
Dimitris
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RE: Aegis Combat System

Post by Dimitris »

....and this is part of the appeal of SM-6 ERAM.
abbafan53
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RE: Aegis Combat System

Post by abbafan53 »

ORIGINAL: Primarchx

Looks like their targets are below the radar horizon before the missiles can engage. Aircraft tend to dive for the deck when targetted by SAMs in Command.

The target aircraft all have illumination vectors - would this be possible if they were below the radar horizon of the parent ship?
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Primarchx
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RE: Aegis Combat System

Post by Primarchx »

ORIGINAL: abbafan53

ORIGINAL: Primarchx

Looks like their targets are below the radar horizon before the missiles can engage. Aircraft tend to dive for the deck when targetted by SAMs in Command.

The target aircraft all have illumination vectors - would this be possible if they were below the radar horizon of the parent ship?

I just watched the missiles in flight in your save game. When missiles were in the basket their targets seemed to be below the radar horizon and they went No Guidance.
abbafan53
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RE: Aegis Combat System

Post by abbafan53 »

[&o]I think you are right - the aircraft (Flankers) are dropping down to 80 feet as the missile approaches, causing it to lose its target lock - hats off to those AI pilots!

According to Wikipedia, the AN/SPY-1B FCR has a maximum range of 45 nm against sea-skimming missiles. In this engagement, the loss-of-lock seems to occur from about 35 nm out. However, I have no doubt that the radar modelling in CMANO is very accurate, so this distance is surely correct.

It seems like a very simple way to defeat such an expensive system - I'm going to reduce the engagement range against fighters to 30 nm, in the hope that less missiles will be wasted.

Thanks to everyone for all the feedback on this.[:)]
sergiopl
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RE: Aegis Combat System

Post by sergiopl »

I´m not sure if it´s an issue or not, but I´ve experienced the same sensation of "missile wasting" than greycat, in a different scenario.

In my case, the vampires are well inside the radar horizon of a Burke when they are detected. The ship starts launching ESSMs. The first ones are guided from the start, and then every one else is "blind". There´s nothing wrong with that, if the "blind" missiles get their illumination for the end game... but this happens only with a few of then.

I think that the problem is that, when the ship starts launching more missiles after the first interceptions, they are guided from the start too... and lots of the missiles that are already closing to their targets never got their terminal guidance: they "lost their turn" to the newly launched. That´s not the way AEGIS works, AFAIK all missiles are "blind" till the end game, when the illuminators handle the terminal guidance sequencially, avoiding such a waste of resources.

In my sandbox scenario, a Burke needed 64 ESSMs to handle 24 Granits, which could be even realistic... as supersonic missiles are difficult to engage, but a high proportion of then never had the chance to intercept. They simply gone "blind" from launching. This is relatively new, because AEGIS always had performed "as adviced" (with SAM engaging targets sequencially) in previous builts.

PS: Running latest Steam available built in the save, but the issue (if it is an issue) persists on 998.2
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SeaQueen
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RE: Aegis Combat System

Post by SeaQueen »

If a SARH missile is flying to a target that is beyond the radar horizon of the surface ship, it probably cannot illuminate it.

The solution is to cut the range of the missile down to something within the radar horizon against a low altitude target (set WRA to ~10-15 NM) or use another ship to illuminate the target, otherwise you run the risk of them breaking lock.
sergiopl
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RE: Aegis Combat System

Post by sergiopl »

ORIGINAL: SeaQueen

If a SARH missile is flying to a target that is beyond the radar horizon of the surface ship, it probably cannot illuminate it.

But the thing is that the targets are well inside the radar horizon: the first missiles, those which are guided from launch, aren´t affected by the "issue" and they hit their targets... or miss them, but they attempt the intercept.

The engagement sequence is something like that:

1) The Burke detects the first incoming missile (a Granit) at 20 nm and starts launching ESSMs. The first 6 are guided from the start by the illuminators (2 against each of the first 3 Granits, consistent with the 3 illuminators). That´s not exactly the way AEGIS works, but it´s irrelevant at this point.

2) The first interception takes place about 10 nm from the ship. Then, the 2nd missile targeted against that particular vampire go astray and 2 of the following (#7 and #8) get their terminal guidance. Everything is going OK to this point.

3) But then... new missiles are launched from the Burke and start getting guidance from the onset, and the missiles already in the air and about to intercept remain "blind", and they can´t engage any target (except for some exceptions).

From my point of view, things should go on as described in point 2: as the ESSMs approach their targets, they should sequentially receive terminal guidance (as the engagements are taking place inside the 10-nm ring, there are no radar horizon issues) on their turn, not losing it to new missiles that should receive guidance later on. As far as I can remember, it was always this way on CMANO, and is the way AEGIS works in real world (at least according to open sources).

PS: Hmmm... I´ve been playing around with some old scenarios of mine, and the results are more or less the same, maybe tilting a bit in favour of the "vampires", but this could even be more realistic. If nobody else has noticed some "disturbance"... maybe it´s only that I´m getting old and touchy [:D]
sergiopl
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RE: Aegis Combat System

Post by sergiopl »

I have another question about the AEGIS combat system, in particular regarding with the range of the SPY-1. In the game it is stated as 175 nm, but I was told by a very reliable source that the real figure is 256 nm. Also, I have found the same data in some online sources (not-so-reliable, to be honest) like this:

https://quizlet.com/64668521/aegisssss-flash-cards/
https://www.studyflashcard.com/flashcar ... deck/12806
https://www.freezingblue.com/flashcards ... tID=309681

The "256" also appears in this apparently much more legit source: https://calhoun.nps.edu/bitstream/handl ... sAllowed=y (but in a somewhat obscure way).

Where did the 175 nm figure come in the first place? Is my info wrong?
thewood1
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RE: Aegis Combat System

Post by thewood1 »

http://missiledefenseadvocacy.org/missi ... y-1-radar/ lists it at about 175nm. So there is that. I have some Jane's books that might list it.

I couldn't find the range reference in the pdf you posted.



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OldSarge
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RE: Aegis Combat System

Post by OldSarge »

A radar's detection range is also affected by the RCS of the target. The range to detect a GEN 5 stealthy fighter will be shorter than detecting an AWACs.

The Aegis SPY-1 RADAR
Detection Range

The only public numerical figure on Aegis detection range against a specific target (that I have seen) is that the SPY-1D “can track golf ball-sized targets at ranges in excess of 165 kilometers.”[26] A golf ball-size (1.68 inches diameter) sphere corresponds to radar cross section of about 0.0025 m2 at 3.3 GHz.[27] This statement was made in the context of the soon-to-be deployed SPY-1D(V) radar to detect mortar and artillery shell and small-caliber rockets against a clutter background, so presumably it applies to the D(V) version. Scaling to a radar cross section more typical of a ballistic missile warhead (0.03 m2 at 3.3 GHz) gives a range of at least 310 km.
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Lowlaner2012
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RE: Aegis Combat System

Post by Lowlaner2012 »

Just a thought...if you think the Aegis system is pumping out to many missiles you could use the WRA settings to fine tune it to your liking...

Cheers :-)
sergiopl
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RE: Aegis Combat System

Post by sergiopl »

I´ve checked the 1989 edition of The Naval Institute Guide to World Naval Weapons Systems and it also states the max range as "reportedly" 175 nm. Maybe this was the figure for an early SPY-1A -my source told me about a SPY-1D(V)- and things have changed since. Or maybe the official downgraded figure is 175 nm... but I´m pretty sure that the real one is 256 nm because my source was VERY reliable (I know, I know... it sounds exactly like typical Internet forum´s bullshit [:D], but it isn´t [;)]). The same happens often with submarine speeds or missile ranges.

Regarding the PDF, the figure appears several times in the formulas (you can find it using Ctrl+F and looking for "256"). For example, on page 49: Y_range (u)? (-256, +256) nm (obscure, as I said, but... coincidence?).

The other sources, as unrealiable they can appear, seems to be something like training tests (I don´t know how could they end appearing online), with apparently quite detailed information. The 512 nm "tracking" range that is mentioned in some of them is quite striking for me, but... could it be the "BMD mode" range?

PS. Another source, for Spanish speakers: http://www.defensa.com/espana/defensa-a ... ana-prueba

Key part: la fragata Blas de Lezo aportaba la capacidad de su dotación y sus sensores, principalmente su radar Lockheed Martin SPY-1D, que con sus 475 kilómetros de alcance refuerza de una manera muy eficaz la capacidad de las estaciones de radar del Ejército del Aire

Translation: the frigate Blas de Lezo provided the capacity of its crew and its sensors, mainly its Lockheed Martin SPY-1D radar, which with its 475 kilometers of range strengthens in a very effective way the capacity of the radar stations of the Air Force

475 km = 256 nm, another coincidence?
thewood1
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RE: Aegis Combat System

Post by thewood1 »

The 256 you are talking about is an upper range for a programming matrix. Not the range of the radar. Just look at the code around it.
sergiopl
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RE: Aegis Combat System

Post by sergiopl »

And what is the "nm" right behind the "256"? It seems like "nautical miles" to me... but I could be wrong, of course.

On the other hand, the Spanish online source that I found clearly states that the range is 475 km. Exactly 256 nm. Exactly the same figure that I was told years ago...

Another source: www.nrotc.web.arizona.edu/data/101/swo_brief.ppt

On the page 16 of the presentation:

AN/SPY-1B radar
Track up to 900 contacts at distance of up to 256 nm


As I said before, I get the feeling that the 175 nm figure was for the SPY-1A. SPY-1B has twice the power, so an increase in range seems plausible.
thewood1
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RE: Aegis Combat System

Post by thewood1 »

It menas its a matrix with units of nm. DO you think it has a range of -256 nm? That doc is a programming guide. What its saying its creating a range from -256 to 256. You might be right about the range, but I would make sure you understand the docs you are throwing around.
thewood1
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RE: Aegis Combat System

Post by thewood1 »

btw, if you think its that important and your sources are solid, take it to the db thread and don't bury it here.
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