微电成像测井仪中数字相敏检波开方算法的改进及DSP实现

Improvement and DSP Realization of Extraction in DPSD of Micro Conduction Image Logging Tool

研究了微电阻率成像测井仪中数字相敏检波开方算法的改进及其DSP实现。介绍了数字相敏检波的基本原理,给出了线性逼近开方算法的优缺点,针对线性逼近算法精度不高的缺点提出一种线性逼近和牛顿拉夫逊相结合的新算法,并给出新算法与线性逼近算法的相对误差图,展现了新算法在计算精度上的优越性,然后给出新算法DSP实现的程序流程图和实验结果。得出新开方算法不仅能够满足测井实时计算的要求,而且还能提高信号检测的线性度的结论。

The improvement and DSP realization of extraction in digital phase sensitivity of the micro conduction image logging tool was studied.The basic theory of DPSD were introduced,and then the advantage and disadvantage of the line-approaching method were mtroduled.Then the paper provided a new method of extraction,showing that the new method is better than the old one through the chart of relative difference.And then provide the flow chart of the new method DSP realization.The experiment results indicate that the new extraction method is better than line-approaching method.It can satisfy the requirement of real-time calculation and can improve the measure linearity.