Novel ray tracing method for stray light suppression from ocean remote sensing measurements

Area of Science:

• Remote Sensing
• Optical Engineering
• Image Analysis

Background:

• Remotely sensed images from the Geostationary Ocean Color Imager exhibit radiance discrepancies at slot boundaries.
• These discrepancies are suspected to stem from stray light effects impacting image quality.

Purpose of the Study:

• To develop and validate a novel in-orbit stray light analysis method for remotely sensed images.
• To identify the causes and quantify the impact of stray light on image data.
• To implement a correction process for radiometric discrepancies caused by stray light.

Main Methods:

• Developed an integrated ray tracing (IRT) technique simulating source, target, and instrument phases.
• Simulated ray paths from the Sun to the instrument detector plane for realistic environmental modeling.
• Validated simulation results by comparing them with actual remotely sensed images.

Main Results:

• Identified a background stray light pattern in cloud-free conditions.
• Simulated variations in stray light patterns with bright target movement, reaching a maximum of 8.5841% in band 2.
• Demonstrated significant reduction in stray light ratios post-correction (e.g., band 6 from 2.38% to 1.02%, band 8 from 1.09% to 0.35%).

Conclusions:

• The IRT-based analysis effectively determines stray light paths and sources in orbit.
• The developed correction process successfully mitigates radiometric discrepancies.
• This technique enhances the reliability and accuracy of remotely sensed image data.