Fig. 1. The 100 m long baseline optical interferometer under construction in China

Fig. 2. Schematic optic layout diagram of optical path difference measurement based on channeled spectrum：

Fig. 3. Numerical simulation results

Fig. 4. Schematic of optical path difference measurement experiment based on channeled spectrum

Fig. 5. The strategy of fringe tracking

Fig. 6. Experimental results of optical path difference extraction in channeled spectrum detection experiment

Fig. 7. The results of the experiment