I wonder what this missile is doing when it flashes twice before impact,
View attachment 172500
I've seen this in other videos but only one flash. Something to do with terminal boosting?
I think the two flashes are from two interceptors' explosions behind the missile. Both missed though.
There were two interceptors visible in the video, one coming from the right and turning upwards, another coming from below. Both interceptors had small flashes. From the trail I can see that the flash of the right one is the point where the interceptor made an extreme turn. So the small flash must be from its vector thruster. This also means that the bottom interceptor must also made an extreme turn causing the small flash.
The two big flashes behind the path of the missile must then be results of explosions of the two interceptors behind the missile warhead.
The following images are frames extracted from your gif. They are listed here in order of time.
Missile warhead in red circle. Interceptor in green circle, bottom interceptor out of frame but visible in later frames.
First explosion of interceptor causing big flash, it is so bright that the missile is invisible.
Afterwards, two interceptors trails are visible.
Explosion of the second interceptor
Trail of the interceptor making turn can be seen. Now this bright spot is the missile warhead. The trail of the interceptor is behind it.
This demonstrates that terminal interception at such high speed and low altitude is matter of luck with low probability
