在超声反射回波的数学模型基础上，利用小波滤波方法对超声信号进行预处理，提取强噪声背景中的弱回波信号。
This paper attempts to preprocess ultrasonic signal by wavelet filtering based on the mathematical model of the ultrasonic echo, extracts weak echoes from signal with high noise background.
较强的降水时段和有效的连续降水将大幅度消弱回波强度，并使其较长时间地维持在低指数状态，其相应能见度也大为改善。
Relatively strong rainfall period and effectively continuous rainfall can make the echo intensity decrease greatly and remain the low index for a long time, and the visibility turns well.
在PD雷达检测中，雷达接收到的回波信号的能量相当弱时，用传统的雷达积累与检测方法不能可靠地检测目标。
In the PD radar detection, when the echo signal energy received is quite weak, the targets cannot be detected reliably with the traditional radar accumulation and detection method.
应用推荐