The ultrahigh-precision distance measurement based on a single laser frequency comb as the multi-wavelength source together with an ultra-highresolution dispersive spectrometer utilizing a virtually imaged phase array (VIPA) was studied numerically. The simulations provide the component parameter optimization and the comb spectral images on a CCD camera. An ameliorated scheme was proposed through achieving real-time comparisons between the

reference and interference signals captured on a camera simultaneously to improve both the measurement accuracy and the precision signi cantly. With the optimized data processing, the proposed approach is especially suitable for serving as a ultra-high precision relative distance measurement, and the measurement resolution can reach picometer scale in the optimal cases.