I guess I mean in the sense of if you have the drones starting position, the end location (or approximate) and movement tracking based on terrain movement, like the cheap version of Tomahawk but instead of having a map you just use relative change from a stereo camera/lidar pointed at the ground to track relative movement? I guess the hardware to run that isn't available in mass production.

I don't think you can do terrain following entirely in software unless you already have an accurate image of what to expect--and a munition will never know the fine detail. (Coarse detail--I would expect you could do a fair job of steering a ballistic missile based on images of the target area. Closest match and figure out in what way the image is stretched is at least theoretically possible with camera + software. Computationally practical, I don't know, nor how accurate it could be.)