一种高精度地震数据采集单元的系统设计与实现

Design and implementation of high precision seismic data acquisition unit system

随着国民经济的发展,矿产资源的勘探迫在眉睫.金属矿地表地质和地下地质的特殊性,勘探具有勘探深度大、分辨率高等特点,常规地震勘探技术不适用于金属矿勘探.因此,必须研制轻便、低成本的高精度地震仪器.而地震数据的采集是地震勘探的重要技术环节,采集单元的技术指标对野外采集的质量至关重要,而数据采集单元的指标高低,绝大部分取决于模数转换单元的选取,因此,本文重点对模数转换单元进行了设计,采用高精度的24位Σ-Δ型ADC进行数据的采集,在分辨率和动态范围上都有了突破,然后采用基于CPLD的数字逻辑设计方式对地震数据进行处理,在硬件方面成功的降低了该采集站电路设计的硬件规模,降低了成本和功耗,然后通过RS-485的数据传输方式进行远程传输,从而将采集数据传送到PC主机.与此同时,在硬件方面,也对整个电路的规模进行了系统优化,并进行了实验仿真,验证了逻辑功能的正确性,增强了系统的可靠性.

With the development of national economy,the exploration of mineral resources is imminent.Due to the metal particularity of surface geology and underground geology,conventional seismic exploration technique is not applicable to metallic ore exploration.Therefore,it is important to develop lightweight,low cost and high precision seismic instrument.Seismic data acquisition is an important technical link in seismic exploration.The technical index of seismic data acquisition station is very important to the quality of the field collection.Most all Indicators depend on the selection of A/D conversion unit.Therefore,this paper focuses on the A/D conversion unit.It uses a high precision Σ-Δ A/D conversion to make a great breakthrough in resolution and dynamic range.And then the digital logic design method based on CPLD is used to deal with seismic data,reducing the hardware scale,cost and power consumption of the acquisition circuit design successfully.Using RS-485 date transmission method to realize the remote transmission,thus the acquisition data is transferred to the PC.At the same time,in terms of hardware,this paper deals with the size of the whole circuit system optimization,and the simulation experiment was performed to verify the correctness of the logic function,enhances the system＇s reliability.