基于过采样的高精度宽动态范围次声信号采集系统

摘要

The infrasound signals detecting system has ultra-high resolution,wide input dynamic range and strong noise rejec-tion abilities In order to improve the ability of existing ADCs to detect infrasound signal,simplify the circuit of system and reduce the cost,over-sampling technique was applied to increase ADC's resolution.By this way,the acquired signals are more similar to the original infrasound signals.And to realize weak signal detection by using over-sampling,the system's PGA gain can be dynamically set based on the amplitude of the input signal.Based on the specific characteristic of the micro controller,the concrete software is provided and tested.Experimental results show that the method of acquiring signals using over-sampling technique can reserve more details than the method of directly acquiring signals,and the system is adaptable to satisfy the research demand of infrasound.%次声电信号的检测要求系统具有极高的分辨率、宽动态范围以及强噪声抑制能力。该系统为了提高现有模数转换器检测次声信号的能力，简化系统电路和降低生产成本，通过过采样来提高ADC的分辨率，实现了对原始次声信号高精度的采集；同时为了避免微弱次声信号幅值太小而导致的过采样失效，该系统增加了根据输入电平变化动态改变增益的功能。文中结合微控制器的特性，给出了具体的实现方法，并对其进行了测试。实验表明，该系统较传统次声信号数据采集系统具有更高的精度，满足了目前对于次声信号研究的需要。