Band shifting for ocean color multi-spectral reflectance data

Area of Science:

• Oceanography
• Remote Sensing
• Optical Physics

Background:

• Ocean remote sensing reflectance (RRS) data are crucial for monitoring marine environments.
• Discrepancies exist between RRS data from different satellite missions due to varying spectral bands.
• Accurate RRS values are essential for bio-optical modeling and understanding ocean processes.

Purpose of the Study:

• To develop and validate a band-shifting scheme for ocean remote sensing reflectance (RRS) in the visible spectrum.
• To enable the estimation of RRS at specific wavelengths using data from neighboring spectral bands.
• To improve the consistency and comparability of RRS data across different satellite missions.

Main Methods:

• Determined inherent optical properties (IOPs) using a bio-optical model.
• Calculated IOPs at target wavelengths based on assumed spectral shapes.
• Employed the bio-optical model in forward mode to derive RRS at the target wavelength.

Main Results:

• The band-shifting scheme achieved high accuracy, with relative errors mostly within 1% for 488-490 nm conversions.
• Conversions in the green spectral domain (547-560 nm) showed errors ranging from 2% to 5%.
• For simulated data with low chlorophyll-a concentrations (<1 mg m⁻³), errors were within 2% for all conversions.
• The scheme significantly improved agreement between RRS data from different satellite missions.

Conclusions:

• The proposed band-shifting method is effective for estimating RRS at unmeasured wavelengths.
• This approach enhances the compatibility of ocean color data from various satellite sensors.
• The method holds promise for more unified and accurate oceanographic research using remote sensing data.