Appendix A — Technical Details

This section provides detailed mathematical formulations, derivations, and supporting information for the FastMAPOL algorithm. The material presented here complements the main chapters and is intended for readers who require a deeper understanding of the underlying theory, assumptions, and implementation details.

The appendices include: - Details in radiative transfer model - Details in the NN and automatic differentation - Detailed formulations of aerosol size distributions and their moments
- Surface reflectance models for ocean and land - Multi-angle atmospheric correction

These technical details are not required for general use or interpretation of the FastMAPOL products but are essential for algorithm development, validation, and advanced scientific analysis.

All equations and formulations follow the conventions introduced in the main text unless otherwise noted.

Each chapter provides an implementation status indicating where the described methodology has been applied or its current stage of development. The status categories include the pre-launch Day-In-The-Life (DITL) test, with data available through OB.DAAC; the operational PACE V3 and PACE V4 products, available through the Earthdata Cloud; methodologies currently under Evaluation; and Planned future developments. When multiple methodological options are available, the Model field identifies the specific model or configuration to which the implementation status applies.

For example:

Implementation status

Model	DITL	PACE V3	PACE V4	Evaluation	Planned
—	x	x	x	—	—