The quality index of grating signal, especially the quality index of grating secondary moire fringe signal is analyzed. The circuit using to dynamically inspect the quality of grating signal is realized by harmonic analysis.

• 对光栅信号的质量指标，主要是对光栅到莫尔条纹信号质量指标进行了分析，并通过采用谐波分析法，对光栅信号质量进行动态综合检测的电路进行了实现。