Frequency Scanning Interferometry Multi-Channel Synchronous Ranging based on Rapid Suppression of Doppler Error

Multi-channel synchronous distance measurement is of great significance for the structural network monitoring of large-scale equipment manufacturing. The precision, efficiency, flexibility of measurement directly impacts the operation quality in manufacturing. In this paper, we propose a multi-channel synchronous rapid absolute distance measurement (ADM) system based on frequency scanning interferometry (FSI). A dual-interferometer structure was presented, by introducing optical intensity splitting inside the measurement interferometer to expand channels, reducing the multi-channel system complexity and ensuring the unity of the traceability chain. The system employs dual-laser interferometric signals mixing after spectral segmentation to achieve rapid suppression of Doppler error during the transmission of optical signal, significantly avoiding complex digital signal processing time for interference-signal overlap and improving the efficiency. To validate the performance of the system, we have employed a simulation to verify the target distance extraction of 10 channels. Subsequently, we conducted distance measurement experiments in different vibration conditions utilizing retroreflectors as the targets. The experimental results demonstrate that the Doppler effect has been significantly suppressed, and the precision of the stationary target reaches 1 μm particularly, indicating that this system has high potential in application for high-precision structural monitoring.