Benthic Habitat Mapping Using Multispectral High-Resolution Imagery: Evaluation of Shallow Water Atmospheric Correction Techniques.

Francisco Eugenio,Dionisio Rodríguez-Esparragón,Javier Marcello,Javier Martin

doi:10.3390/s17112639

Francisco Eugenio, Dionisio Rodríguez-Esparragón + Show 2 more

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https://doi.org/10.3390/s17112639

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Abstract

Remote multispectral data can provide valuable information for monitoring coastal water ecosystems. Specifically, high-resolution satellite-based imaging systems, as WorldView-2 (WV-2), can generate information at spatial scales needed to implement conservation actions for protected littoral zones. However, coastal water-leaving radiance arriving at the space-based sensor is often small as compared to reflected radiance. In this work, complex approaches, which usually use an accurate radiative transfer code to correct the atmospheric effects, such as FLAASH, ATCOR and 6S, have been implemented for high-resolution imagery. They have been assessed in real scenarios using field spectroradiometer data. In this context, the three approaches have achieved excellent results and a slightly superior performance of 6S model-based algorithm has been observed. Finally, for the mapping of benthic habitats in shallow-waters marine protected environments, a relevant application of the proposed atmospheric correction combined with an automatic deglinting procedure is presented. This approach is based on the integration of a linear mixing model of benthic classes within the radiative transfer model of the water. The complete methodology has been applied to selected ecosystems in the Canary Islands (Spain) but the obtained results allow the robust mapping of the spatial distribution and density of seagrass in coastal waters and the analysis of multitemporal variations related to the human activity and climate change in littoral zones.

Highlights

Coastal ecosystems are characterized by high biodiversity and primary production
Given the importance of coastal water ecosystems for life quality and the global climate, systematic and efficient information is important for the monitoring of such protected areas
For most potential users of high-resolution images in coastal monitoring and, WorldView-2 imagery, we found that these studies mainly covered some methods, typically applied to mapping vegetation and they did not assess, in detail, the influence of the atmosphere conditions in littoral zones water-leaving radiances

Summary

Introduction

Coastal ecosystems are characterized by high biodiversity and primary production. The capability to map and monitor these benthic environments is fundamental for developing the corresponding management policies [1,2]. In this context, satellite remote sensing is a useful technology to monitor such coastal shallow ecosystems [3]. Satellite remote sensing is a useful technology to monitor such coastal shallow ecosystems [3] These areas are challenging as turbidity is usually present and, to derive parameters such as bathymetry or bottom features, the effects of the water column have to be accounted for

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