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Decoys are greatly over-rated in ballistic missile systems. Sensors are so good at discriminating decoys from warheads that decoys are largely ineffective and h

Decoys are greatly over-rated in ballistic missile systems. Sensors are so good at discriminating decoys from warheads that decoys are largely ineffective and have been for decades. This has borne out in Ukraine. A decoy sufficiently sophisticated to look real to good sensors will have weight and characteristics that approach that of a real warhead, at which point you might as well add another warhead. Decoys only make sense if the marginal cost of adding them is low.

srean 7mo ago
I would like to understand this more. How are decoys discriminated? The acceleration due to gravity is the same for all. Radar reflectance could be manipulated. Drag and lift perhaps, but can't those be matched with the real thing ? What is it that gives up a decoy as a decoy ? Yes I can distinguish a falling feather from a falling lead-shot. The more interesting questions is can one not make a featherweight that falls like lead-shot, reflects like lead-shot and be cheaper than lead-shot. For a warhead decoy ten times lighter it needs to present an area ten times smaller to maintain drag induced deceleration parity. For radio parity the decoy needs to reflect more the actual warhead reflect less. Metal coated kevlar ribbons on the decoy might do it. What I find interesting is that the curse of rocket equation makes decoys pretty expensive to propel. So if I am forced to incur that cost anyway, might as well put a real warhead on that.
- jandrewrogers 7mo ago
  The terminal guidance systems use broad-spectrum imagers to identify warheads and select their point of impact. Radar is only used to point them in the general direction. Against this type of terminal guidance, a decoy must have the same shape, size, orientation, and spectral signature of a warhead, and maintain these properties while being ablated. As a matter of engineering, a decoy with these properties will necessarily have mass and volume costs that approach that of a warhead, with none of the benefits of a warhead. From a weapon design perspective, effective decoys significantly reduce the range of the missiles they are attached to. That is not a tradeoff any weapon designers are willing to make because range is one of the most critical attributes of an effective weapon.
  - srean 7mo ago
    Even if the problem of an effective decoy ballistic warhead could be solved, it will a still quite costly to get it "there" at "that" speed. Might as well fill it with high explosives. Appreciate your reply.

srean 7mo ago

I would like to understand this more. How are decoys discriminated? The acceleration due to gravity is the same for all. Radar reflectance could be manipulated. Drag and lift perhaps, but can't those be matched with the real thing ? What is it that gives up a decoy as a decoy ? Yes I can distinguish a falling feather from a falling lead-shot. The more interesting questions is can one not make a featherweight that falls like lead-shot, reflects like lead-shot and be cheaper than lead-shot. For a warhead decoy ten times lighter it needs to present an area ten times smaller to maintain drag induced deceleration parity. For radio parity the decoy needs to reflect more the actual warhead reflect less. Metal coated kevlar ribbons on the decoy might do it. What I find interesting is that the curse of rocket equation makes decoys pretty expensive to propel. So if I am forced to incur that cost anyway, might as well put a real warhead on that.

jandrewrogers 7mo ago
The terminal guidance systems use broad-spectrum imagers to identify warheads and select their point of impact. Radar is only used to point them in the general direction. Against this type of terminal guidance, a decoy must have the same shape, size, orientation, and spectral signature of a warhead, and maintain these properties while being ablated. As a matter of engineering, a decoy with these properties will necessarily have mass and volume costs that approach that of a warhead, with none of the benefits of a warhead. From a weapon design perspective, effective decoys significantly reduce the range of the missiles they are attached to. That is not a tradeoff any weapon designers are willing to make because range is one of the most critical attributes of an effective weapon.
- srean 7mo ago
  Even if the problem of an effective decoy ballistic warhead could be solved, it will a still quite costly to get it "there" at "that" speed. Might as well fill it with high explosives. Appreciate your reply.