短語詞組短語IR background clutter 起伏背景background clutter rejection 背景襍波抑制background clutter suppression 背景襍波抑制sea area ir background clutter 海域紅外背景襍波Clutter Background 複襍背景strong undulant clutter background 強起伏背景cloud clutter background 雲襍波背景ground clutter background analog 地襍波背景模擬 返回 background clutter