harbor defense observation station

coastal and harbor defense operations

harbor defense command post

harbor defense controlled mine

observation point / observation post (OP)

harbor (harbour)

harbor defence

harbor master

harbor minesweeper

Pearl Harbor

harbor area

inner harbor area

air harbor

harbor

harbor pilotage

unmanned harbor security vehicle

total station (TS) / total station theodolite (TST)

air-defense early warning station

perimeter defense (all-around defense)

beach defense mine / beach-defense mine

close observation

command-and-observation post

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

hostile observation

infrared night vision observation device

observation aircraft (O; obsn acft)

observation facilities

observation flight

observation patrol

observation satellite

observation slit

supervise the observation of armistice conditions

type of observation