Research on measurement algorithm of digital level

Aiming at reading data automatically with digital level, the localization principles of reading data automatically with digital level based on double sinusoidal code ruler are studied. Firstly, The edge position of bar code on ruler is detected with wavelet transform. Secondly, The phase difference of double sinusoidal code is calculated with Short-Time Fourier Transform (STFT). Finally, Based on the one to one corresponding relationship of the phase difference and the position on ruler, the line of sight height is obtained. The experiment results indicate that the measurement algorithm is feasible.