Calibration method of microgrid polarimeters with image interpolation.

Area of Science:

• Optics and Photonics
• Image Sensor Technology

Background:

• Microgrid polarimeters offer advantages like snapshot capability and no moving parts over conventional systems.
• However, microgrid polarimeters are susceptible to errors including fixed pattern noise (FPN), photon response nonuniformity (PRNU), pixel cross talk, and instantaneous field-of-view (IFOV) error.

Purpose of the Study:

• To propose and validate a novel characterization method for enhancing measurement accuracy in visible waveband microgrid polarimeters.
• To address and mitigate common error sources affecting microgrid polarimeter performance.

Main Methods:

• Camera calibration using uniform illumination to ensure uniform sensor response and eliminate initial IFOV error.
• Implementation of a spline interpolation method specifically designed to minimize residual instantaneous field-of-view (IFOV) error.
• Characterization and validation of the method's effectiveness in reducing FPN and PRNU.

Main Results:

• The proposed calibration technique successfully created a uniform sensor response across the entire field of view.
• Spline interpolation effectively reduced the instantaneous field-of-view (IFOV) error.
• Experimental results demonstrated a significant minimization of both fixed pattern noise (FPN) and photon response nonuniformity (PRNU).

Conclusions:

• The developed characterization method is effective in improving the measurement accuracy of microgrid polarimeters in the visible spectrum.
• The approach successfully mitigates key error sources, paving the way for more reliable polarimetric measurements.
• This work contributes to advancing the performance and applicability of snapshot microgrid polarimetry.