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 uncha