Radiance-ratio algorithm wavelengths for remote oceanic chlorophyll determination

Area of Science:

• Oceanography
• Remote Sensing
• Spectroscopy

Background:

• Accurate oceanic chlorophyll determination is crucial for understanding marine ecosystems and water quality.
• Existing remote sensing algorithms for chlorophyll estimation face challenges in diverse oceanic regions.

Purpose of the Study:

• To evaluate two-band radiance-ratio algorithms for remote oceanic chlorophyll determination.
• To identify optimal spectral bands for chlorophyll estimation using airborne active-passive data.

Main Methods:

• Utilized airborne active-passive (laser-solar) data from various oceanic regions.
• Generated 2-D chlorophyll-fluorescence and radiance-ratio statistical correlation matrices.
• Analyzed all possible two-band ratio combinations from 32 contiguous passive bands.

Main Results:

• Closely spaced radiance-ratio bands showed high correlation with laser-induced chlorophyll fluorescence.
• Yellow (~565/575-nm), orange-red (~675/685-nm), and red (~695/705-nm) bands show promise for Case II waters.
• Blue-green radiance ratios (~490/500-nm) were effective for Case I waters with limited data.

Conclusions:

• Specific two-band radiance ratios are effective for remote chlorophyll estimation.
• Optimal band combinations vary depending on oceanic water type (Case I vs. Case II).
• This research advances remote sensing capabilities for monitoring ocean chlorophyll.