Alternative measuring method for water-leaving radiance using a radiance sensor with a domed cover

Area of Science:

• Oceanography
• Remote Sensing
• Optical Oceanography

Background:

• Accurate measurement of water-leaving radiance is crucial for ocean color remote sensing.
• Traditional methods for measuring water-leaving radiance can be complex and require empirical adjustments.

Purpose of the Study:

• To validate a novel above-water sensor method for directly measuring water-leaving radiance.
• To assess the accuracy and practical advantages of the proposed method compared to existing techniques.

Main Methods:

• Field experiments were conducted in Katagami Bay.
• An above-water sensor with a black domed cover was used to directly measure radiance.
• Measurements were compared with data obtained from vertical profiles of upwelling radiance.

Main Results:

• The proposed method yielded radiance values slightly lower than those from vertical profiles.
• Self-shading by the instrument's shape was identified as the cause for the underestimation.
• The method demonstrated advantages by eliminating empirical processes and minimizing manual post-measurement work.

Conclusions:

• The above-water sensor method provides a valid approach for measuring water-leaving radiance.
• The method offers a simplified and more direct alternative to traditional techniques.
• Further refinement of instrument design could mitigate self-shading effects.