EO in orbit: Scientific webinars -
Overview
- Type: Webinar
- Theme: Aquatic environments
- Date:
- Time: 11:00 a.m. to noon (ET)
- Duration: 1 hour
- Cost: Free
- Location: Virtual
- Language: French and English
- Target audience: Industry, academic institutions, media, not for-profit organizations, scientists, government
Summary
Presentations will focus on scientific developments in the field of Earth Observation for aquatic environments.
Detailed description
Presentations:
- Remote sensing of aquatic environments
- A probabilistic approach to retrieve water optical parameters and bathymetry from remote sensing reflectance in optically complex shallow waters
Remote sensing of aquatic environments
Presentation 1 (in French)
From 11:00 to 11:30 a.m.
Dr. Simon Bélanger
Professor in the Department of Biology, Chemistry and Geography; BORÉAS research group on northern environments (home entity: Université du Québec à Rimouski); Québec-Océan: Quebec inter-institutional group on oceanographic research
Optical multispectral satellite remote sensing of aquatic environments has been the subject of research and development since the late s. Initially limited to the high seas, technological advances over the past 10 years have allowed for the development of applications for coastal, lake, and even river environments.
The presentation will cover remote sensing of these environments and the associated key challenges that remain. It will identify what variables can be extracted from satellite data that provide information about water quality, i.e. dissolved organic matter, suspended solids and concentration of chlorophyll a. In addition to optical quality of the water, satellite data can also, under certain conditions, yield information related to bathymetry and habitats in littoral areas.
The primary methods used to obtain aquatic variables will be presented, as well as their limitations and particulars in the context of different applications. Several examples of applications will be presented. Lastly, the main available and forthcoming satellite platforms will be presented, with the perspectives that hyperspectral data provide.
A probabilistic approach to retrieve water optical parameters and bathymetry from remote sensing reflectance in optically complex shallow waters
Presentation 2 (in English)
From 11:30 a.m. to noon
Soham Mukherjee, Ph.D. Scholar
Department of Biology, Chemistry and Geography; BORÉAS research group on northern environments (home entity: Université du Québec à Rimouski); Québec-Océan: Quebec inter-institutional group on oceanographic research
Dr. Simon Bélanger
Professor in the Department of Biology, Chemistry and Geography; BORÉAS research group on northern environments (home entity: Université du Québec à Rimouski); Québec-Océan: Quebec inter-institutional group on oceanographic research
Remote sensing reflectance (Rrs) is often employed for retrieving water column properties in optically complex waters.
This includes:
- Inherent optical properties (IOPs), like non-water absorption, and particulate backscatter
- Biogeochemical (BGC) variables, like chlorophyll concentration
- Bottom depth and benthic reflectance in optically shallow waters
In state-of-the-art methods to invert the Radiative Transfer Equation, e.g., grid search with Look-Up Tables or optimization of an objective function, various combinations of parameters (IOPs, BGC variables, and shallow water properties) can yield similar Rrs in shape and magnitude. This "ill-posed" problem introduces uncertainty in inversion retrievals.
The presentation proposes a Bayesian inversion for optically complex waters, yielding probability densities of IOPs/BGCs and shallow parameters as solution for the given Rrs observation that characterizes the degree of uncertainty in the retrieved parameters.