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Random question - anyone know how a sidewinder missile hits these objects (whatever they are)? My missile knowledge is non-existent but movies show me it has so

Random question - anyone know how a sidewinder missile hits these objects (whatever they are)? My missile knowledge is non-existent but movies show me it has something to do with heat signature - which these don’t seem to have.

zmanian 4y ago
The AIM-9X is infrared imaging based rather than heat signature based. The pilot resolves that contrast between the object and sky before firing the missile and missile targets the object based on the image.
- lost_tourist 4y ago
  Do you know what sets it off? Seems like it wouldn't be from impact as these balloon materials couldn't be comparable to say hitting another plane, right?
  - justin66 4y ago
    https://en.wikipedia.org/wiki/Proximity_fuze https://en.wikipedia.org/wiki/Proximity_fuze
  - r00fus 4y ago
    These payloads are duds - all you need to do is to pierce the balloon.
    - pixl97 4y ago
      A little research on the Canadian Ballon shootdown a number of years back show that isn't exactly the case. A larger balloon was shot with a (20mm I believe) cannon and continued to float a long distance.
    - implements 4y ago
      ‘Duds’ is an odd way of putting it. Sidewinders usually have an ‘exploding ring of metal rod’ warhead, I believe - and that was replaced by something else better suited to destroying the balloon while leaving the payload intact enough for technical analysis.
  - jandrewrogers 4y ago
    All modern missiles use a proximity fuse that selects the optimum position relative to the target to detonate, it isn't based on contact. One thing to consider is that the warhead is not in the nose -- that is where the sensors are -- but further back on the missile. These warheads often us an annular (ring-like) blast pattern, hence why positioning and orientation relative to the target at detonation time is important to maximize damage.
  - dharmab 4y ago
    The AIM-9X uses an IR proximity fuse.
  - s1artibartfast 4y ago
    Adding to janderwogs response, air intercept missiles don't really deal damage with the explosion. The missiles are built with shrapnel payloads propelled by the explosion. These are what actually damage the aircraft on the receiving end.
- bmitc 4y ago
  > The AIM-9X is infrared imaging based rather than heat signature based. Isn't heat detected by infrared? What's the difference?
  - Sharlin 4y ago
    Cloudless sky is cold, and at 30,000 feet extremely cold. Anything not-sky is going to contrast against the sky, even if it has no internal heat source (and remember: if it has electric things in it, it produces heat).
  - hammock 4y ago
    Yes warm bodies put off infrared, but so does the sun, and the suns IR rays are reflected by objects just as they are in the visible range. These reflections used for imaging
  - aembleton 4y ago
    The balloon reflects IR, just as it reflects visible light
deleted 4y ago
[deleted]
giantrobot 4y ago
The missiles seek and track based on heat differences. To an IR sensor the sky is typically pretty "cold" and just about anything in the sky is relatively "hot". Once the missile is locked onto the relatively hot signature against the cold background the sensor stares at it and adjusts the missile's trajectory to intercept it (and blow up). Countermeasures like flares try to trick a missile's sensor into thinking the hot object it was staring at was the flare going that way and not the maneuvering aircraft going the other way. Modern IR tracking missiles try to stay locked on the object by ignoring hotter or cooler objects that might end up in its view.
- azalemeth 4y ago
  At FL400+, anything not the earth is basically space – if you point an IR camera in the sky outwards, it really does look very cold as the pressure is basically zero and scattered IR photons are few and far between. Objects that are not vacuum have a signature in the IR – both a black-body temperature (which, even at ~ -55 ºC, is a hell of a lot higher than single-digit kelvin…) and possibly the opportunity to reflect any incident light.
- jandrewrogers 4y ago
  Some modern imaging-based guidance packages for anti-aircraft missiles use multiple spectra to defeat countermeasures like flares. While a flare and a plane sometimes look similar in IR, they are easy to discriminate in the UV spectrum.
rocket_surgeron 4y ago
Not much is known of the AIM-9X but it is probably similar to the AIM-9L. The AIM-9L doesn't lock on to the hottest thing, it takes an IR picture of the scene and follows the targeted "blob" in the image that's generated. Additionally it has laser proximity fusing so it knows when it is close to the shape it is tracking. By not simply picking the hottest thing in a scene you can't hide in front of the sun anymore, and the effectiveness of flares is reduced. The only thing needed to generate a "blob" good enough to target is sufficient ΔT between the scene and the targeted object. The objects, and they have been curiously consistent with calling them "objects", definitely have sufficient ΔT compared to the background sky if they are made of any solid material that has been exposed to sunlight for any period of time.
- nickpeterson 4y ago
  Not to sound like a Redditor, but this username checks out.
porbelm 4y ago
Well it goes real noisy like NEERRRRRERERRRRRERRRRERRRRwarblewarblewarble and something gets hit. I thought it knew where it wasn't but that's the Tomahawk. The Sidewinder just knows where thing is. That's the extent of my knowledge about the AIM-9 Sidewinder.

zmanian 4y ago

The AIM-9X is infrared imaging based rather than heat signature based. The pilot resolves that contrast between the object and sky before firing the missile and missile targets the object based on the image.

lost_tourist 4y ago
Do you know what sets it off? Seems like it wouldn't be from impact as these balloon materials couldn't be comparable to say hitting another plane, right?
- justin66 4y ago
  https://en.wikipedia.org/wiki/Proximity_fuze https://en.wikipedia.org/wiki/Proximity_fuze
- r00fus 4y ago
  These payloads are duds - all you need to do is to pierce the balloon.
  - pixl97 4y ago
    A little research on the Canadian Ballon shootdown a number of years back show that isn't exactly the case. A larger balloon was shot with a (20mm I believe) cannon and continued to float a long distance.
  - implements 4y ago
    ‘Duds’ is an odd way of putting it. Sidewinders usually have an ‘exploding ring of metal rod’ warhead, I believe - and that was replaced by something else better suited to destroying the balloon while leaving the payload intact enough for technical analysis.
- jandrewrogers 4y ago
  All modern missiles use a proximity fuse that selects the optimum position relative to the target to detonate, it isn't based on contact. One thing to consider is that the warhead is not in the nose -- that is where the sensors are -- but further back on the missile. These warheads often us an annular (ring-like) blast pattern, hence why positioning and orientation relative to the target at detonation time is important to maximize damage.
- dharmab 4y ago
  The AIM-9X uses an IR proximity fuse.
- s1artibartfast 4y ago
  Adding to janderwogs response, air intercept missiles don't really deal damage with the explosion. The missiles are built with shrapnel payloads propelled by the explosion. These are what actually damage the aircraft on the receiving end.
bmitc 4y ago
> The AIM-9X is infrared imaging based rather than heat signature based. Isn't heat detected by infrared? What's the difference?
- Sharlin 4y ago
  Cloudless sky is cold, and at 30,000 feet extremely cold. Anything not-sky is going to contrast against the sky, even if it has no internal heat source (and remember: if it has electric things in it, it produces heat).
- hammock 4y ago
  Yes warm bodies put off infrared, but so does the sun, and the suns IR rays are reflected by objects just as they are in the visible range. These reflections used for imaging
- aembleton 4y ago
  The balloon reflects IR, just as it reflects visible light

deleted 4y ago

[deleted]

giantrobot 4y ago

The missiles seek and track based on heat differences. To an IR sensor the sky is typically pretty "cold" and just about anything in the sky is relatively "hot". Once the missile is locked onto the relatively hot signature against the cold background the sensor stares at it and adjusts the missile's trajectory to intercept it (and blow up). Countermeasures like flares try to trick a missile's sensor into thinking the hot object it was staring at was the flare going that way and not the maneuvering aircraft going the other way. Modern IR tracking missiles try to stay locked on the object by ignoring hotter or cooler objects that might end up in its view.

azalemeth 4y ago
At FL400+, anything not the earth is basically space – if you point an IR camera in the sky outwards, it really does look very cold as the pressure is basically zero and scattered IR photons are few and far between. Objects that are not vacuum have a signature in the IR – both a black-body temperature (which, even at ~ -55 ºC, is a hell of a lot higher than single-digit kelvin…) and possibly the opportunity to reflect any incident light.
jandrewrogers 4y ago
Some modern imaging-based guidance packages for anti-aircraft missiles use multiple spectra to defeat countermeasures like flares. While a flare and a plane sometimes look similar in IR, they are easy to discriminate in the UV spectrum.

rocket_surgeron 4y ago

Not much is known of the AIM-9X but it is probably similar to the AIM-9L. The AIM-9L doesn't lock on to the hottest thing, it takes an IR picture of the scene and follows the targeted "blob" in the image that's generated. Additionally it has laser proximity fusing so it knows when it is close to the shape it is tracking. By not simply picking the hottest thing in a scene you can't hide in front of the sun anymore, and the effectiveness of flares is reduced. The only thing needed to generate a "blob" good enough to target is sufficient ΔT between the scene and the targeted object. The objects, and they have been curiously consistent with calling them "objects", definitely have sufficient ΔT compared to the background sky if they are made of any solid material that has been exposed to sunlight for any period of time.

nickpeterson 4y ago
Not to sound like a Redditor, but this username checks out.

porbelm 4y ago

Well it goes real noisy like NEERRRRRERERRRRRERRRRERRRRwarblewarblewarble and something gets hit. I thought it knew where it wasn't but that's the Tomahawk. The Sidewinder just knows where thing is. That's the extent of my knowledge about the AIM-9 Sidewinder.