This lecture will provide an overview of atmospheric correction approaches for remote sensing of water properties for open oceans and coastal waters. Beginning with definitions of some basic parameters for describing ocean and atmosphere properties, the radiative transfer equation (RTE) for ocean‐atmosphere system will be introduced and discussed. Various methods for solving RTE, in particular, the successive‐order‐of‐scattering method will be described. We examine various radiance contribution terms in atmospheric correction, i.e., Rayleigh scattering radiance, aerosol radiance (including Rayleigh‐aerosol interaction), whitecap radiance, sun glint, and water‐leaving radiance. Atmospheric correction algorithms using the near‐infrared (NIR) and shortwave infrared (SWIR) bands will be described in detail, as well as some examples from MODIS‐Aqua measurements. The standard NIR atmospheric correction algorithm has been used for deriving accurate ocean color products over open oceans for various satellite ocean color sensors, e.g., OCTS, SeaWiFS, MODIS, MERIS, VIIRS, etc. Some specific issues of atmospheric correction algorithm over coastal and inland waters, e.g., highly turbid and complex waters, strongly absorbing aerosols, will also be discussed. The outline of the lectures is provided below.

Outline of the Lectures

Introduction
Brief history
Basic concept of ocean color measurements
Why need atmospheric correction
Radiometry and optical properties
Basic radiometric quantities
Apparent optical properties (AOPs)
Inherent optical properties (IOPs)
Optical properties of the atmosphere
Molecular absorption and scattering
Aerosol properties and models
Non‐ and weakly absorbing aerosols
Strongly absorbing aerosols (dust, smoke, etc.)
Radiative Transfer
Radiative Transfer Equation (RTE)
Various approaches for solving RTE
Successive‐order‐of‐scattering method
Single‐scattering approximation
Sea surface effects
Atmospheric diffuse transmittance
Normalized water‐leaving radiance
Atmospheric Correction
Define reflectance and examine the various terms
Single‐scattering approximation
Aerosol multiple‐scattering effects
Open ocean cases: using NIR bands for atmospheric correction
Coastal and inland waters
Brief overviews of various approaches
The SWIR‐based atmospheric correction
Examples from MODIS‐Aqua measurements
Addressing the strongly‐absorbing aerosol issue
The issue of the strongly‐absorbing aerosols
Some approaches for dealing with absorbing aerosols
Examples of atmospheric correction for dust aerosols using MODIS‐Aqua and CALIPSO data
Requirements for future ocean color satellite sensors
Summary

Bibliography

Chandrasekhar, S. (1950), “Radiative Transfer,” Oxford University Press, Oxford, 393 pp. Van de Hulst, H. C. (1980), “Multiple Light Scattering,” Academic Press, New York, 739pp.

Gordon, H. R. and A. Morel (1983), “Remote Assessment of Ocean Color for Interpretation of Satellite Visible Imagery: A Review,” Springer‐Verlag, New York, 114pp.

Gordon, H. R. and M. Wang (1994), “Retrieval of water‐leaving radiance and aerosol optical thickness over the oceans with SeaWiFS: A preliminary algorithm,” Appl. Opt., 33, 443‐452.

Gordon, H. R. (1997), “Atmospheric correction of ocean color imagery in the Earth Observing System era,” J. Geophys. Res., 102, 17081‐17106.

Wang, M. (2007), “Remote sensing of the ocean contributions from ultraviolet to near‐infrared using the shortwave infrared bands: simulations,” Appl. Opt., 46, 1535‐1547.

IOCCG (2010), “Atmospheric Correction for Remotely‐Sensed Ocean‐Color Products,” Wang, M. (ed.), Reports of International Ocean‐Color Coordinating Group, No. 10, IOCCG, Dartmouth, Canada.
(http://www.ioccg.org/reports_ioccg.html)