artillery observation post

observation point / observation post (OP)

artillery group observation post

artillery groupment observation post

artillery observation post vehicle

forward artillery observation post

mobile artillery observation post

vehicle-mounted artillery observation post

command-and-observation post

control observation post

air observation post observer

amount of command of observation post

antiaircraft observation post

battery observation post

cross-observation post

flash-spotting observation post

fort-observation post

forward observation post

forward observation post observer

groupment observation post

armored observation post

sound ranging observation post

air observation post

air observation post flight

air observation post squadron

command p.-observation post

scientific observation post

aiming post lamp / aiming post light

forward observer (FO), forward observation officer; (artillery) observer / spotter

artillery observation unit

field artillery observation battalion

forward artillery observation point

anti-aircraft artillery observation aircraft