This Algorithmic Theoretical Basis Document (ATBD) describes the algorithm used to estimate chlorophyll content over land from Level-1 OLCI products from the Sentinel-3 mission. The algorithm called the OLCI Terrestrial Chlorophyll Index (OTCI) is a unique chlorophyll index for OLCI data. This document identifies the source of input data; outlines the physical principles and mathematical background; justifies this algorithm and then explores its limitations and assumptions.
Photosynthetically Active Radiation (PAR) reaching the ocean surface is defined as the quantum energy flux from the Sun in the spectral range 400-700 nm; units are Einstein/m2/day. PAR is essential for the carbon-cycle modellers to convert the measured chlorophyll concentration into an estimate of ocean productivity, and hence of carbon sequestration.
The purpose of this ATBD is to define the approach to white cap correction that could be applied to OLCI.
This document aims at providing a comprehensive description of the OLCI instrument's spectral characteristics and their potential impact on algorithms likely to expect data acquired at a constant wavelength.
It describes an algorithm that (a) properly accounts for the instrument spectral characterisation to convert TOA radiances into TOA reflectances and (b) provides a first order correction of the TOA reflectance for the wavelength variation, accounting for the surface underneath.
This ATBD discusses the potential approaches to correct sun glint for OLCI. The amount of sun glint will be reduced as compared to MERIS; the field-of-view (FOV) is tilted to reduce the sun-glint pollution (maximum Operating Zenith Angle, OZA, of 55°).
This ATBD describes a procedure to derive the bi-directional water leaving radiance reflectances (RL_w) from top of atmosphere (TOA) radiance reflectance spectra RL_toa (L1b data) of the Ocean Land Colour Imager (OLCI) on Sentinel 3. The procedure is an alternative method to the standard atmospheric correction procedure for OLCI. Its main purpose is to improve the atmospheric correction over turbid and highly absorbing case 2 water and for areas of an image which are contaminated by sun glint. However, it can be applied also to case 1 water.
Showing 161 - 166 of 166 results.
Most Accessed Publications