在雷达信号检测中，当外界干扰强度变化时，雷达能自动调整其灵敏度，使雷达的虚警概率保持不变。具有这种特性的接收机称为恒虚警接收机。(In radar signal detection, the radar can automatically adjust its sensitivity when the external interference intensity changes, so that the radar's false alarm probability remains unchanged. The receiver with this characteristic is called a constant false alarm receiver.)