核磁共振测井仪采集信号去噪处理方法

De-noising Method of Nuclear Magnetic Resonance (NMR) Logging Signal

核磁共振信号处理技术中,滤波器起到了重要的作用。采用积分梳状滤波器(CIC)和有限长单位冲激响应数字滤波器(FIR)进行多重处理,充分利用CIC滤波器仅有加法运算,减少了大量的乘法运算,提高了系统的运算速度,降低了系统的功耗。分析级联CIC和FIR数字滤波器的设计原理,用FPGA进行硬件设计,通过Matlab仿真对FIR数字滤波器窗函数进行选取,成功运用于核磁共振测井仪器。

Filters play a very important role in processing NMR data.Most of the time the comb integral filter(CIC)and FIR digital filter are used for multiple processing of NMR data.Taking full advantage of CIC filter,not only can reduce a large number of multiplications,improve system operation speed,but also can reduce consumption of system power.Based on the analysis of design principles of concatenated comb integral filter and FIR digital filter,this paper using the FPGA to design the hardware and selecting the window function of FIR digital filter through Matlab simulation,which are successfully applied to filter the noise of NMR logging tool.