在存在界面(或)底面时,用现有的时间反转法进行超声自适应聚焦的目标探测时,虽然可以获得处理增益,但却不能区分目标和界面(或底面)。这是因为界面反射波和目标反射波将完全相干叠加在一起形成相干峰。普通超声脉冲反射法在检测接近于界面的目标时也有同样的缺点。本文提出了一个改进的时间反转法即换元接收的时间反转法,这时界面反射波的相干峰将消失,因此它可以实现在有界面时目标是否存在的鉴别。 In the presence of an interface (or bottom), the target time and the interface (or bottom) can not be distinguished from each other although the processing gain can be obtained by using the conventional time-reversed method for ultrasonic adaptive focusing. This is because the interface reflections and the target reflections will be completely coherently superimposed together to form a coherent peak. Common ultrasonic pulse reflection method in the detection of the target near the interface also have the same shortcomings. In this paper, an improved time reversal method is proposed, ie, the time reversal method of receiver reception. At this moment, the coherent peak of interface reflection wave will disappear, so it can realize the identification of the existence of the target when there is an interface.