High-range-resolution velocity-estimation techniques for coherent Doppler lidars with exponentially shaped laser...

Area of Science:

• Atmospheric Science
• Optical Remote Sensing

Background:

• Coherent Doppler lidar systems measure atmospheric wind profiles.
• Accurate velocity measurements are crucial for weather and climate studies.
• Current methods are limited by laser pulse length, affecting resolution.

Purpose of the Study:

• To develop novel algorithms for recovering nonuniform Doppler-velocity profiles.
• To improve the resolution of lidar measurements beyond the conventional pulse-length limitation.
• To assess algorithm performance under realistic conditions, including noise.

Main Methods:

• Analysis of autocovariance of complex heterodyne lidar signals.
• Development of new algorithms for Doppler-velocity profile retrieval.
• Computer simulations using modeled and real exponentially shaped laser pulses.
• Evaluation of performance considering additive noise and radial velocity fluctuations.

Main Results:

• Novel algorithms successfully recover Doppler-velocity profiles.
• Achieved resolution is significantly shorter than the lidar pulse length.
• Algorithm performance is robust against additive noise and velocity fluctuations with sufficient signal averaging.
• Demonstrated efficiency through simulations with various pulse models.

Conclusions:

• The developed algorithms offer superior resolution for Doppler-velocity lidar measurements.
• These techniques overcome traditional limitations imposed by laser pulse length.
• The findings enable more precise atmospheric profiling with coherent Doppler lidar.