Airborne system for multispectral, multiangle polarimetric imaging.

Area of Science:

• Optics and Remote Sensing
• Oceanography and Water Quality Monitoring
• Instrument Development

Background:

• Accurate characterization of water constituents is crucial for environmental monitoring.
• Multispectral polarimetry offers a novel approach to retrieve information on particle size and type.
• Existing remote sensing techniques may have limitations in providing detailed water constituent information.

Purpose of the Study:

• To design, fabricate, calibrate, and deploy an airborne multispectral polarimetric imager.
• To assess the instrument's capability in providing information about water constituents.
• To validate the instrument's performance against established models.

Main Methods:

• Utilized four 16 MP cameras with wire grid polarizers for polarization state separation.
• Incorporated a five-position filter wheel with narrow-band spectral filters (435, 550, 625, 750 nm).
• Employed a programmable stage for controlled view angles (±65° from nadir) and processed data for polarimetric signatures.

Main Results:

• The instrument successfully measured polarimetric signatures as a function of view zenith and azimuth angles.
• Validation against Monte Carlo code showed agreement, including the presence of neutral points.
• Achieved a random error level better than 0.25% in the measured degree of linear polarization (8% at 435 nm).

Conclusions:

• The developed airborne multispectral polarimetric imager is a viable tool for water constituent analysis.
• The instrument demonstrates high accuracy and reliability in measuring polarization signatures.
• This technology has the potential to significantly advance water quality monitoring and research.