Just a couple of things I'm a little unsure of
1) How to get level 3 detailed scans
2) What's the difference between the Advanced discovery scanner and the Intermediate discovery scanner
thank you.
1) Level 2 and Level 3 scans are not currently in the game. There is only one Detailed Surface Scanner, which will give you more details on the surface of a planet / moon than the base scan you are able to do without one.
2) The differences between the discovery scanners are how far out they will detect unexplored objects relative to your position in the system:
Basic Discovery Scanner - Has a 500 LS range and costs 1,000 CR
Intermediate Discovery Scanner - Has a 1000 LS range and costs ~500,000 CR
Advanced Discovery Scanner - Has a system-wide range and costs ~1,500,000 CR