observation balloon

(military) A type of balloon that is employed as an aerial platform for intelligence gathering and artillery spotting.

Japanese Meaning

偵察気球：軍事用に用いられる気球で、情報収集や砲兵観測を目的として空中に浮かべられる。

The regiment relied on an observation balloon to direct artillery fire across the foggy valley.

連隊は、霧に包まれた谷で砲撃を指示するために観測気球に頼った。

Sense（1）

(military) A type of balloon that is employed as an aerial platform for intelligence gathering and artillery spotting.

observation balloons

（ plural ）