[rich_sasha]

I don’t want to labour the point as I’m no expert, but is it enough to be close enough to the target and lock on? The rocket has some amount of kinetic energy for manoeuvering, and presumably less at the terminal stage. If the initial radar fix puts it in the wrong position/velocity relative to the target, can it make up for it with its own late lock-on?

I understood this is why you need that precise radar fix: you need a pretty good idea of the target trajectory so the chasing missile is not only in the right place, but also flying at an advantageous angle relative to its target.

As for on-missile guidance, I thought that was a thing since a long time ago? The radar guides initially, then the final stage is done by the rocket. Is there something newer/different now?

[sudosysgen]

Until pretty recently, missile used semi-active guidance. Basically, they would have a receptor that would detect the radiation scattered back from radar. The issue in this case is that the signal would not be much more precise or even usable due to the low frequency. So active guidance fully from the missile is needed.

Ground based missiles are quite different from A2A missiles in that they are much larger and have much more kinetic energy to spare.

Maneuvering always kills kinetic energy though. So what these missiles do is that they gain altitude before maneuvering, reducing speed and drag, and once the maneuver is done (lock acquired), they maneuver and gain a lot of kinetic energy by coming back down.

There is basically zero chance a ground based missile fired from 50-60 km will lack energy even if it has to maneuver a few hundred meters to correct for inaccuracy.