noun, noun or participle which takes 'suru', transitive verb, intransitive verb
Primarily used for military or coast guard patrols by ships or aircraft. Can be used as a noun or with する as a transitive/intransitive verb.
海上自衛隊が東シナ海を哨戒している。
The Maritime Self-Defense Force is patrolling the East China Sea.
A patrol aircraft conducted a surveillance flight over the territorial airspace.