Multiple scattering from Chebyshev particles: Monte Carlo simulations for backscattering in lidar geometry.

Area of Science:

• Atmospheric Optics
• Light Scattering
• Remote Sensing

Background:

• Lidar measurements commonly assume no multiple scattering and spherical particles.
• These assumptions are often violated in real-world atmospheric conditions.

Purpose of the Study:

• Investigate multiply-scattered lidar returns from nonspherical particles.
• Quantify the impact of particle shape on backscattered signal intensity and depolarization.

Main Methods:

• Utilized T(2) Chebyshev particles and reviewed their single-scattering properties.
• Employed a Monte Carlo procedure to simulate backscattered signals for various fields of view.
• Compared results with scattering from equivalent spheres and validated with double scattering analytical formulas.

Main Results:

• Demonstrated significant variability in multiply-scattered signal intensity due to particle deformation.
• Observed striking effects on depolarization, particularly at moderate optical depths.
• Confirmed sensitivity of depolarization to minor deviations from sphericity, even with random particle orientation.

Conclusions:

• Particle non-sphericity strongly influences lidar signal intensity and depolarization.
• Standard lidar assumptions may lead to inaccuracies when dealing with nonspherical particles.
• Accurate lidar interpretation requires considering particle shape effects in multiple scattering scenarios.