First results from a dual photoelastic-modulator-based polarimetric camera

Area of Science:

• Optics and Photonics
• Remote Sensing Technology
• Atmospheric Science

Background:

• Remote sensing of atmospheric aerosols requires precise polarization measurements.
• Existing systems face challenges in accuracy and spectral range.
• Development of advanced polarimetric cameras is essential for improved aerosol characterization.

Purpose of the Study:

• To report the construction and calibration of a novel dual photoelastic-modulator (PEM)-based polarimetric camera.
• To establish a prototype for a multispectral system for airborne and spaceborne aerosol remote sensing.
• To achieve high uncertainty within +/-0.005 for degree of linear polarization (DOLP) measurements.

Main Methods:

• Integration of a dual-PEM assembly with a low-polarization reflective telescope.
• Utilizing a miniaturized focal-plane assembly with spectral filters and patterned wire-grid polarizers.
• Employing a custom push-broom detector array for radiometric and polarimetric data acquisition.
• Calculating normalized Stokes parameters (q and u) and subsequently DOLP and angle of linear polarization.

Main Results:

• Successful construction and calibration of the dual-PEM polarimetric camera operating at 660 nm.
• Demonstration of both intensity and polarization imaging capabilities.
• Achieved uncertainty within +/-0.005 for DOLP over a wide range.
• Presented laboratory test data, calibration results, and outdoor imagery.

Conclusions:

• The developed dual-PEM polarimetric camera prototype meets the stringent accuracy requirements for aerosol remote sensing.
• The system provides a robust platform for future multispectral polarimetric remote sensing missions.
• The achieved precision in DOLP measurement is a significant advancement for atmospheric aerosol studies.