High-precision long distance measurement based on broad spectrum interferometry using a femtosecond laser

Abstract

The method based on broad spectrum interference using femtosecond pulses is an important ranging method. In this paper, we experimentally evaluate the effect of interferometric spectral bandwidth used for calculation on the ranging results, and precision can be improved by choosing the optimal spectral bandwidth. In addition, in order to eliminate the influence of interferometric spectral fluctuations on the measurement results, we introduce the detrend algorithm into the processing algorithm and compare the measurement results before and after the algorithm improvement. Then, four kinds of nominal distance were measured and the contribution of the relevant factors to the measurement uncertainty is evaluated. Finally, the synthetic standard uncertainty of measurement results was 0.02 μm, 0.10 μm, 1.05 μm and 2.78 μm for nominal distance of ~0 m, ~1.5 m, ~16.5 m and ~43.5 m respectively.