Reconnaisance is the gathering of information about the enemy and terrain. Ideally you would obtain this information without the enemy's knowledge, but it may be necessary to fight for it, particularly when you wat to determine the type and extent of enemy fiorces in an area.
Observation posts can be as good as mobile recon.... depending on the terrain. They need to:
Negative information is just as important as reports of contacts.
It's a good idea to have fire support (mortars) on hand and in position to help your recon force retreat from enemy contact. In this situation, laying down smoke and shells would be helpful.