Bomb damage assessment (BDA), also known as battle damage assessment, is the practice of assessing damage inflicted on a target from a stand-off weapon, most typically a bomb or air launched missile. It is part of the larger discipline of combat assessment. Assessment is performed using many techniques including footage from in-weapon cameras, gun cameras, forces on the ground near the target, satellite imagery and follow-up visits to the target. Preventing information on battle damage reaching the enemy is a key objective of military censorship. For nuclear weapons special techniques may be required due to the extensive damage caused and difficulty in approaching the site.