Phase-Shift Laser Ranging Technology Based on Multi-Frequency Carrier Phase Modulation

Compared to traditional phase laser ranging technology, phase-shift laser ranging technology based on carrier phase modulation has significant advantages, such as simple modulation and demodulation, as well as simultaneous ranging and velocity measurements with high precision. To expand the range and ensure the ranging precision in carrier phase modulation in phase-shift laser ranging technology, we propose a phase-shift laser ranging system based on multi-frequency carrier phase modulation. We analyzed the effects of the stagger coefficient, modulation depth, and signal-to-noise ratio on the ranging precision by simulation. Finally, we built an experimental system with a range of 300 m by choosing appropriate parameters and conducting linearity and range precision tests. The experimental results show that the system has good linearity, and the ranging precision can reach 1 cm when the signal-to-noise ratio is 20 dB.