When looking at the process, it’s actually bonkers in a totally differet direction.
Any laser shot from Earth ends up spread out an area of about 26km diameter on the lunar surface. So you need a high-power laser pulse to get any sort of concentration of photons to hit the lunar surface that are detectable there. Then the reflection gets spread out over a similar large area on reflection to Earth, so you’re trying to detect a few photons from the original laser pulse of 1017 photons (or whatever the actual number is).
So to your question about sighting - actually not necessary. But you’ve turned the laser pulse into a photon shotgun, which is equally bonkers. You’re shooting a pinpoint laser that still spreads out to the size of a large city just to hit a meter or two-sized target. Then the same thing again just to get the reflection.
When looking at the process, it’s actually bonkers in a totally differet direction.
Any laser shot from Earth ends up spread out an area of about 26km diameter on the lunar surface. So you need a high-power laser pulse to get any sort of concentration of photons to hit the lunar surface that are detectable there. Then the reflection gets spread out over a similar large area on reflection to Earth, so you’re trying to detect a few photons from the original laser pulse of 1017 photons (or whatever the actual number is).
So to your question about sighting - actually not necessary. But you’ve turned the laser pulse into a photon shotgun, which is equally bonkers. You’re shooting a pinpoint laser that still spreads out to the size of a large city just to hit a meter or two-sized target. Then the same thing again just to get the reflection.