artillery instrumental observation

instrumental observation

instrumental observation and survey battery

artillery instrumental reconnaissance

instrumental registration

instrumental velocity

observation point / observation post (OP)

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

artillery observation post

artillery observation unit

field artillery observation battalion

forward artillery observation point

anti-aircraft artillery observation aircraft

artillery group observation post

artillery groupment observation post

artillery observation

artillery observation aeroplane

artillery observation aircraft

artillery observation helicopter

artillery observation plane

artillery observation post vehicle

artillery observation tank

artillery observation tower

artillery observation vehicle

artillery reconnaissance and observation

forward artillery observation post

mobile artillery observation post

vehicle-mounted artillery observation post

artillery forward observation officer

main artillery (major caliber artillery)

artillery and rocket artillery

close observation

command-and-observation post