BAER Processor Overview

Introduction

The purpose of the BAER processor is to implement Integrated BAER algorithm (IBAER) which estimates the surface reflectances and two parameters that allow to characterise the aerosols contained in the atmosphere from MERIS Level-2 data. The processor is applicable to both, MERIS Level-2 full and reduced resolution data.

The parameters derived by the algorithm and variables estimated are:

• The Aerosol Optical thickness (τ), which is defined as the integrated extinction coefficient over a vertical column of unit cross section
• The Angstrom coefficient, which is an exponent that expresses the spectral dependence of aerosol optical thickness (τ) with the wavelength of incident light (λ). The spectral dependence of aerosol optical thickness can be approximated by, τ_α = β λ^α where α is the Angstrom exponent and β is the aerosol optical thickness at 1 μm. The Angstrom exponent provides additional information on the particle size (larger the exponent, the smaller the particle size), aerosol phase function and the relative magnitude of aerosol radiances at different wavelengths.
• The surface reflectances in the MERIS channels, except channels 11 and 15.

References

Von Hoyningen-Huene, W., Kokhanovsky, Burrows, J.P., Berthelot, B., Regner, P., Baret, F. (2005) Aerosol optical thickness retrieval over land: The atmospheric correction based on MERIS L2 reflectance. Proc. of MERIS/AATSR Workshop 2005, ESA ESRIN 26.-30. Sept. 2005, ESA SP-597, Dec. 2005.

Documentation provided for the BAER processor on the BEAM plug-ins page.

More Information

More information about the MERIS BAER processor implementation can be found in these chapters:

1. BAER Algorithm
2. BAER Processor