精密相干检测法研究

On precision coherent detection method

研究了精密相干检测法的原理,即采用共时钟方案,使与发送机有关的参考信号同接收机接收到的待测信号精密相干,同时精确检测出复合波信号中各主要谐波的振幅和相位.应用结果表明:该方法克服了微弱复合波信号的锁相放大、数据采集、叠加平均和获取多参数时遇到的困难,提高了观测系统的灵敏度、测量精度、抗干扰能力、探测分辨率和探测深度;精密相干检测法原理同样适用于其他观测系统和对其他类型信号的检测.

The principle of precision coherent detection method, as well as its application and examples is described in this paper. Using a special synchronizing system designed for both transmitter and receiver, which is called one clock timing system, the error caused by lock-in amplifier, data acquisition and stacking is overcome easily and the amplitude and phase of the main harmonics contained in the multi-wave signals are detected successfully in measurement. In the meantime, the instrument applied in the experiments has high sensitivity and high precision, in which the transmitter transmits multi-wave current, and the receiver measures multi-wave signals. Through precision coherent detection, the depth estimation, noise rejection and anomalous discrimination are improved obviously in geophysical prospecting.