A fast and accurate radiative transfer model for aerosol remote sensing

Area of Science:

• Earth and Atmospheric Sciences
• Remote Sensing
• Radiative Transfer Modeling

Background:

• Existing global aerosol retrieval algorithms rely on computationally intensive Look-Up-Table (LUT) techniques.
• There is a need for fast and accurate analytical radiative transfer models for non-polarimetric instruments (e.g., OLCI/Sentinel-3, MSG/SEVIRI).
• Current methods require high-performance computing, limiting near-real-time processing.

Purpose of the Study:

• To develop a Fast and Accurate Semi-analytical Model of Atmosphere-surface Reflectance (FASMAR) for efficient aerosol remote sensing.
• To enable near-real-time generation of global aerosol products without high computational resource demands.
• To provide a "FIRST-LOOK" aerosol product with improved speed and accuracy.

Main Methods:

• Developed FASMAR based on a successive order of scattering technique.
• Calculated the first three orders of scattering exactly.
• Estimated higher orders of scattering using extrapolation and a correction function.

Main Results:

• FASMAR demonstrated a percentage error within ±3% for top-of-atmosphere reflectance compared to SCIATRAN.
• Accuracy remained within ±5% even for solar/viewing zenith angles greater than 70°.
• The model is suitable for typical surfaces and aerosol optical thicknesses.

Conclusions:

• FASMAR offers a fast and accurate alternative to LUT-based methods for aerosol remote sensing.
• The model's efficiency supports near-real-time processing and generation of global aerosol products.
• FASMAR is a valuable tool for instruments like OLCI and MSG/SEVIRI, enhancing aerosol monitoring capabilities.