Subcarrier modulation based phase-coded coherent lidar.

Area of Science:

• Optics and Photonics
• Signal Processing
• Remote Sensing Technology

Background:

• Coherent lidar systems are crucial for high-resolution remote sensing.
• Traditional systems face challenges with Doppler tolerance and Nyquist sampling.
• Non-quadrature receivers and undersampling present unique signal processing hurdles.

Purpose of the Study:

• To develop a lean subcarrier modulation-based phase-coded coherent lidar system.
• To overcome limitations of low Doppler tolerance and sub-Nyquist sampling ratios.
• To demonstrate efficient phase acquisition free from frequency aliasing.

Main Methods:

• Utilizing lean subcarrier modulation and phase-coded signals.
• Employing a non-quadrature receiver architecture.
• Implementing pulse compression to extract phase information.
• Performing validation experiments using inverse synthetic aperture lidar (ISAL).

Main Results:

• Phase information was successfully obtained after pulse compression.
• The mirror frequency introduced by real sampling was rendered negligible.
• Experimental validation using ISAL yielded imaging resolution superior to 4 cm.
• The system demonstrated efficient phase acquisition without frequency aliasing.

Conclusions:

• The proposed lean subcarrier modulation lidar system effectively acquires phase information.
• The system achieves high-resolution ISAL imaging with undersampling.
• This approach offers a promising solution for advanced coherent lidar applications.