Why can't A2A missiles have both?

Theoritically speaking i don't see a problem with having more than one method of guidance for more accurate and jam proof missile. A point in case i s cruise missiles which use three or four guidance systems to compliment each other.

I think the biggest hurdle could be (specially in the case of Short range AAM) the space constraint.How to fit in two guidance systems in an already compact design?

IMO, a BVRAAM with command guided INS for midphase flight guidance and an IR seeker for terminal guidance is a lot more useful. This kind of missile won't give you any warning at all. The fighter's radar would direct the missile after launch towards the target. Once the missile is within the seeker's acquisition basket, the seeker turns on and acquires the target, so called lock after launch capability.

crobato said:

IMO, a BVRAAM with command guided INS for midphase flight guidance and an IR seeker for terminal guidance is a lot more useful. This kind of missile won't give you any warning at all. The fighter's radar would direct the missile after launch towards the target. Once the missile is within the seeker's acquisition basket, the seeker turns on and acquires the target, so called lock after launch capability.

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Is not the case with some BVRAAMs currently??

Also, is it possible to use some passive method to guide the missile until it reaches it's terminal phase. Say, using IRST to guide the missile.

crobato said:

IMO, a BVRAAM with command guided INS for midphase flight guidance and an IR seeker for terminal guidance is a lot more useful.

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Such missiles are obsolete. Examples for such missiles are the Soviet P-6D Progress and P-5 cruise missiles. They used a datalink/INS for mid-course guidance and radar-seeker for terminal guidance.

The datalink was for communication with the launch-aircraft. By the time the missile reached the vicinity of the target, it turned an active-radar seeker and used "logic" (essentially intelligent guesswork) to determine where the target must have moved to since the time it was launched.

Now, ALL cruise, AA, A2G, SAM missiles are fire-and-forget.
Datalink with the source aircraft and logic-guessing at the terminal-phase is not used anymore.

This kind of missile won't give you any warning at all. The fighter's radar would direct the missile after launch towards the target. Once the missile is within the seeker's acquisition basket, the seeker turns on and acquires the target, so called lock after launch capability.

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Such missiles are termed as passively guided missiles and are obsolete, because they are not fire-and-forget missiles. The launching aircraft has to guide the missile even after its launch and hence cannot concentrate on anything else until the missile has acquired the target.

An example is the AIM Sparrow.

Modern missiles such as the AiM-120 have their own seekers and can guide themselves to the target. The launching aircraft can make a U-turn after they are launched.

Theoritically speaking i don't see a problem with having more than one method of guidance for more accurate and jam proof missile. A point in case i s cruise missiles which use three or four guidance systems to compliment each other.

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Modern cruise missiles do not use IR/radar seekers in tandem. In-fact many do not possess any kind of seekers (although the Brahmos does have radar seeker for terminal guidance to locate ships).

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The following is an interesting guidance mechanism of an old Soviet cruise missile, the P-500. If I am not mistaken, US missiles never pioneered such technologies :

The flight profile of the missile varies from 30 to 7,000 m (low-low or low-high). Guidance is based on a digital INS on a gyro- stabilized platform and an active-radar seeker, which periodically switches to passive mode. For the first time, the missile was equipped with a digital computer (Tsifrova Vichislenna Mashina, "digital computing device"). The guidance system was also equipped with a datalink to communicate between missiles in a salvo, with a salvo consisting of eight missiles launched at short intervals. Usually, one of the missiles flies high (5,000-7,000 m) to pick up the target, while the rest remain at medium to low altitude with their radar seekers switched to passive mode. The leading missile then transmits targeting data to the others and allocates individual targets, with half of the salvo directed at the aircraft carrier and half at other ships in the area, one apiece. The onboard radar seekers are turned on at the last moment, just before reaching the target. If the lead missile is shot down, another one (in a programmed sequence) takes over and climbs to a higher altitude to continue directing the salvo. All the missiles have active radar jamming to disrupt any defensive action from fighters and shipboard air-defense systems.

Source:


It must be noted that this kind of guidance was widely used on other Soviet cruise missles. Other missiles like the Yakhont, P-700 and P-1000 adopted similar guidance mechanisms.

---"Quote:
Originally Posted by crobato
IMO, a BVRAAM with command guided INS for midphase flight guidance and an IR seeker for terminal guidance is a lot more useful.

Such missiles are obsolete. Examples for such missiles are the Soviet P-6D Progress and P-5 cruise missiles. They used a datalink/INS for mid-course guidance and radar-seeker for terminal guidance."----

so you're saying that AIM-210, R-77, SD-10, MICA, Meteor, Harpoon, Tomahawk, YJ-8X, and countless other currently fielded/soon to be fielded systems are obsolete?

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I guess I'll have to say this, AGAIN. Fire and Forget is a capability, not the ONLY mode of operation. Missile seekers DO NOT HAVE TO POWER TO DETECT A TARGET AT STANDOFF RANGE, AND MUST RELY ON MID COURSE GUIDANCE.

*************** You have crossed it the last time we "discussed" guidance methods; I guess you just like to jump across lines. Why don't you go read some technical information on missiles before posting?

Try not to get angry so often Yue.

Indianfighter said:

Modern cruise missiles do not use IR/radar seekers in tandem. In-fact many do not possess any kind of seekers (although the Brahmos does have radar seeker for terminal guidance to locate ships).

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Tomahawk cruise missile makes use of a radar for TERCOM guidance and in terminal phase uses infrared image seeker with DSMAC (Digital Scene Matching Area Correlator) for removing the accumulative error of Inertial guidance.

I hope you consider Tomahawk to be modern enough.

Here is a picture which shows an infrared image seeker.



Read up if you want the entire webpage and it mentions time and again that Inertial guidance/TERCOM(radarbased guidance)/DSMAC/infrared imaging seeker are used all together.

Maybe a design similar to the German ARMIGER under development could work !?






Deino

vincelee said:

I'm going to put an end to this, and if IndianFighter reads this, and EVER says anything about mid course guidance being obsolete, someone PLEASE punch him in the face. I would actually settle with just banning him.

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As Mahatma Gandhi said, try to make peace with your aggressor, and hence I shall attempt to do so now.

Moskit

A slightly different case. This thing's terminal stage is actually linked to the ship, since there isn't enough onboard processing power to discriminate between targets.

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And this was the type of missiles that I said are now obsolete (even if in use, the technology has long been surpassed).

Dont feel bad, but I think that in your excitement to prove me wrong, I dont think you read the next 2 paras that I wrote :

" The datalink was for communication with the launch-aircraft. By the time the missile reached the vicinity of the target, it turned an active-radar seeker and used "logic" (essentially intelligent guesswork) to determine where the target must have moved to since the time it was launched.

Now, ALL cruise, AA, A2G, SAM missiles are fire-and-forget.
Datalink with the source aircraft and logic-guessing at the terminal-phase is not used anymore. "

Anyway, even the sentence that you quoted, I said " obsolete like the P-6D progress and P-5 ". These are not in production any more, and a far cry from the examples of AIM-120 and R-77, Mica etc. that you gave.

I suggest that you also read the example of the Soviet P-500 that I provided.

Please keep the discussion technical from now on, and may not we enter heated discussions.
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Tomahawk cruise missile makes use of a radar for TERCOM guidance and in terminal phase uses infrared image seeker with DSMAC (Digital Scene Matching Area Correlator) for removing the accumulative error of Inertial guidance.

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That is incorrect. The land-attack version of the Tomahawk uses a radar altimeter (for TERCOM ), and the anti-ship version uses IR seeker for ships (during terminal phase).
The DSMAC is not a seeker, but a different guidance technology.

This is from your own source:

All versions have 250 nm+ class range, the land attack versions using TERCOM/INS/DSMAC guidance, the antiship version using datalink midcourse and Imaging Infra-Red (IIR) terminal guidance.

The AGM-109L is the USN's air launched weapon and is configured in two basic versions. The land attack version uses the same TERCOM/inertial/DSMAC guidance as TLAM/C and also the standard warhead, the mission profile and type of target are also identical. The anti-shipping version uses a data-link for midcourse guidance and an IIR seeker, modified from the AGM 65D Maverick missile, for terminal guidance.

Source:
As provided by Maglomanic.

Anyway, as I said earlier, multiple seekers in cruise-missiles are not possible and the age has come, where cruise missiles dont need any seekers at all.

An example is the Tomahawk, which has replaced TERCOM --that uses radar altimer--for GPS guidance.
Of course the anti-ship version may continue to use the IR seeker for ships (and Brahmos will use a radar seeker for ships).

One option under review as an alternative to TERCOM is the use of the Navstar Global Positioning System (GPS) L-band satellite navigation system. GPS offers 15m positioning accuracy virtually worldwide and would eliminate the need for a costly global mapping exercise.

Source:
As provided by Maglomanic.
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Regarding the Arminger missile, it is an anti-radiation missile.

A dual-mode seeker featuring RF homing and bispectral imaging infrared (IIR) capabilities.
The window for the IIR seeker element is inset on the side of the nose at an angle from the direction of flight to reduce friction heating that might confound the sensor.
The RF seeker element will be used to get the missile to the target area, while the IIR seeker element will be used for terminal attack.

Source:


Now the Arminger shall also use GPS guidance :

It will be preprogrammed with target area coordinates and "forbidden" areas by the launch aircraft before firing.

Source:
Same as above.

The logic of using an IIR seeker for an anti-radiaiton missile is not clear. The IIR shall be used for terminal guidance. But why is the need for it, when the target is likely to be emitting radio-waves continously ?

crobato said:

IMO, a BVRAAM with command guided INS for midphase flight guidance and an IR seeker for terminal guidance is a lot more useful.

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Yes I agree. That would be the best type for no-warning engagement. And you won't run into the problem of having to put both a radar receiver and IR seeker in the same missile. I believe there are also some missiles with command guidance modes where you don't have to lock on to the target at all, just designate it. With that combination, the target will receive no warning at all. However, INS may be a bit inaccurate especially for fast and manoeuvrable A2A missiles...

Indianfighter said:

Such missiles are obsolete. Examples for such missiles are the Soviet P-6D Progress and P-5 cruise missiles. They used a datalink/INS for mid-course guidance and radar-seeker for terminal guidance.

The datalink was for communication with the launch-aircraft. By the time the missile reached the vicinity of the target, it turned an active-radar seeker and used "logic" (essentially intelligent guesswork) to determine where the target must have moved to since the time it was launched.

Now, ALL cruise, AA, A2G, SAM missiles are fire-and-forget.
Datalink with the source aircraft and logic-guessing at the terminal-phase is not used anymore.

Click to expand...

Looks like you're a bit confused about active/passive guidance. It's a common misconception. Actively guided doesn't mean the missile is 100% effective if you fire and break lock immdediately upon launch. Yes AMRAAM has its own seeker, but its range is only about 15-20km. You have the option of either guiding the missile using your plane's radar until it reaches 15-20km within target, or you can break lock immediately and run. The latter works, but it's not as accurate as the former, because if you break lock before the missile has locked on to target using its OWN seeker (remember, only has 15-20km range), the missile uses INS only and tries to guess where the target will be in the next few minutes, and at the same time it scans the area with its own radar in hopes of acquiring the target again. While in INS it will only take into account where the fighter was going WHEN you break lock. If the fighter decides to turn the other way AFTER you break lock then the missile wouldn't know and it will most likely miss.

Think of this as guiding a near sighted guy. You can guide him until he can see the target by himself, or you can tell him the general direction of the target then leave him alone, and he walks in the direction until he can find it.

Wingman the example which you gave was good (vincelee's was rude), but I am refering to missiles like the P-6D and P-500, where an operator guides the missile to the source aircraft. These systems are now out of production.

The P-6 and P-35 missiles, which differ only in minor ways, were fitted with the same guidance system and warhead.
When a target was acquired, the operator on the ship verified whether it was the desired target (e.g., the aircraft carrier in the group). If so, the operator designated it as such and turned the missile's seeker on automatic-track mode. Thereafter, the missile descended to low altitude, remaining at supersonic speed.

Source:


The Moskit also works on the same principle.

P-6, P-35 Progress Guidance : Mid-course autopilot (some versions with command update by datalink)
Source:
Same as above.

Command update by datalink means that the target is designated manually by a personnel in the launchi-aircraft (a bomber in this case).
Only the Arrow BMD works in this way, in which a soldier can point the target to a missile that is in flight.