Polarization lidar operation for measuring backscatter phase matrices of oriented scatterers

Area of Science:

• Atmospheric optics
• Lidar remote sensing
• Polarization techniques

Background:

• Accurate characterization of atmospheric particles is crucial for climate modeling.
• Lidar measurements are often limited by assumptions about particle orientation.
• Existing lidar systems may not capture the full polarization state of backscattered light.

Purpose of the Study:

• To implement and demonstrate a novel lidar polarization technique.
• To measure all unique elements of the volume backscatter phase matrix.
• To enable detection of preferential particle orientation in atmospheric volumes.

Main Methods:

• Adaptation of a polarization technique using Mueller calculus.
• Modification of a high spectral resolution lidar at NCAR.
• Instrument characterization to ensure measurement accuracy.

Main Results:

• Demonstration of the technique using a modified lidar system.
• Observation of flattened raindrops with preferential orientation.
• Detection of preferentially oriented ice crystals in an ice cloud.

Conclusions:

• The developed lidar polarization technique successfully measures the volume backscatter phase matrix.
• This capability enhances the detection of oriented particles like ice crystals and raindrops.
• The technique shows potential for improving scattering inversions in atmospheric remote sensing.