频率扫描干涉中基于DFT的相位测量  

Phase measurement in frequency-sweeping interferometry based on DFT

作　　者：王林春[1] 江月松[1] 郭泾平[2] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191 [2]中国空间技术研究院,北京100094

出　　处：《应用光学》2010年第5期757-761,共5页Journal of Applied Optics

基　　金：中国科学院知识创新项目(AA20090024)

摘　　要：频率扫描干涉可以实现绝对距离测量,其中相位测量至关重要,其精度直接影响干涉测量的最终精度。从信号频域角度出发,提出了一种利用参考信号和测量信号离散傅里叶变换的相位测量方法。在对参考信号和测量信号采样前,分别对它们进行负向过零检测,当信号负向过零时才开始采样。对信号离散傅里叶变换后进行频谱分析,指出在信号采样前进行负向过零检测,可以消除信号频率值的相对偏差。根据理论分析,在LabVIEW中进行了建模仿真。结果表明:该方法具有精度高和抗噪声能力强等优点,在测量距离为10 m时,相位测量平均值与理论值相差2π,相对不确定度仅为0.105%。Frequency-sweeping interferometry can be used to measure absolute distance and phase measurement plays an important part in it,because the precision of phase directly influences the precision of distance.The paper puts forward a new phase measurement method making use of Discrete Fourier Transform of reference signal and measurement signal.It does not start to sample until each signal crosses zero negatively.After the spectrum analysis,relative errors can be eliminated if zero-crossings can be tested before sampling signals. According to the theory,the paper has made simulations in LabVIEW,and the results show that the method has the advantages of high precision and good ability to overcome the noise.When the distance is 10 m,the difference between the average of the measured phase and ideal value is 0.2π,and relative uncertainty is 0.105%.

关 键 词：绝对距离测量 相位测量 频率扫描 离散傅里叶变换 

分 类 号：TN247[电子电信—物理电子学]