Dual-frequency AMCW concurrent ranging and velocimetry for LiDAR imaging

Area of Science:

• Optics and Photonics
• Remote Sensing Technology
• Laser Systems Engineering

Background:

• Continuous-wave (CW) Light Detection and Ranging (LiDAR) systems face challenges with Doppler shift from moving targets, impacting ranging accuracy.
• Conventional Amplitude-Modulated Continuous-Wave (AMCW) LiDAR struggles to simultaneously achieve precise ranging and velocimetry due to Doppler interference.

Purpose of the Study:

• To develop a novel LiDAR scheme for concurrent, accurate laser ranging and velocimetry.
• To overcome the limitations imposed by Doppler shift in conventional CW LiDAR systems.

Main Methods:

• Proposing a Dual-Frequency source Amplitude Modulation (DFAM) scheme.
• Utilizing a low-frequency modulation component for Doppler shift quantification and velocity measurement.
• Employing a high-frequency modulation component for phase-difference measurement between transmitted and echo signals.
• Compensating phase differences using the measured Doppler shift for precise distance calculation.

Main Results:

• Achieved highly precise velocimetry with consistency within millimeters per second.
• Maintained ranging accuracy comparable to static target conditions.
• Successfully implemented the DFAM scheme in LiDAR imaging for multi-dimensional object reconstruction.

Conclusions:

• The DFAM scheme effectively enables simultaneous laser ranging and velocimetry in CW LiDAR systems.
• This method significantly improves the performance of LiDAR systems dealing with moving targets.
• The technology has potential applications in advanced LiDAR imaging and analysis.