Iterative retrieval method for ocean attenuation profiles measured by airborne lidar.

Area of Science:

• Ocean optics and remote sensing
• Lidar technology applications
• Bio-optical modeling

Background:

• Ocean color remote sensing lacks vertical structure information.
• Lidar offers vertical profiling but requires inversion methods for optical properties.
• Accurate retrieval of attenuation and backscatter from lidar signals is challenging.

Purpose of the Study:

• To develop and demonstrate a novel iterative retrieval method for deducing the attenuation coefficient from ocean lidar return signals.
• To improve the accuracy of ocean optical property inversion from lidar data.
• To analyze the influence of key parameters on the retrieval accuracy.

Main Methods:

• An iterative retrieval method was developed to calculate the logarithmic backscatter-to-attenuation ratio (k) using a bio-optical model.
• Lidar raw data was processed to derive attenuation coefficients.
• In situ measurements were used to validate the lidar-retrieved attenuation coefficients.

Main Results:

• The iterative method achieved a correlation coefficient (R) of 0.8 and a root mean square error (RMSE) of 0.032 when compared to in situ measurements.
• The parameter k was identified as the primary source of error in lidar return inversion.
• The developed method provides a more accurate estimation of k, thereby enhancing the inversion accuracy of the lidar attenuation coefficient.

Conclusions:

• The new iterative retrieval method significantly improves the accuracy of ocean attenuation coefficient retrieval from lidar data.
• Accurate estimation of the backscatter-to-attenuation ratio (k) is crucial for reliable lidar-based ocean optical property analysis.
• This method enhances the capability of lidar remote sensing for characterizing vertical ocean optical structures.