Evaluation of Satellite-Derived Bathymetry from High and Medium-Resolution Sensors Using Empirical Methods

Evagoras Evagorou,Diofantos Hadjimitsis,Athanasios Argyriou,Nikos Papadopoulos,George Alexandrakis,Christodoulos Mettas

doi:10.3390/rs14030772

Evagoras Evagorou, Diofantos Hadjimitsis + Show 4 more

Open Access

https://doi.org/10.3390/rs14030772

Copy DOI

Abstract

This study evaluates the accuracy of bathymetric maps generated from multispectral satellite datasets acquired from different multispectral sensors, namely the Worldview 2, PlanetScope, and the Sentinel 2, in the bay of Elounda in Crete. Image pre-processing steps were implemented before the use of the three empirical methods for estimating bathymetry. A dedicated correction and median filter have been applied to minimize noise from the sun glint and the sea waves. Due to the spectral complexity of the selected study area, statistical correlation with different numbers of bands was applied. The analysis indicated that blue and green bands obtained the best results with higher accuracy. Then, three empirical models, namely the Single Band Linear Algorithm, the Multiband Linear Algorithm, and the Ratio Transform Algorithm, were applied to the three multispectral images. Bathymetric and error distribution maps were created and used for the error assessment of results. The accuracy of the bathymetric maps estimated from different empirical models is compared with on-site Single beam Echo Sounder measurements. The most accurate bathymetric maps were obtained using the WorldView 2 and the empirical model of the Ratio Transform algorithm, with the RMSE reaching 1.01 m.

Highlights

Publisher’s Note: MDPI stays neutralBathymetry measurements in oceans, rivers, or lakes are essential, especially in coastal areas with intense use of the coastal zone, heavy sea traffic, and vulnerable natural ecosystems
Oftenstep displayed as scatteredbecause, bright spots or white stripes edge the wave. This was implemented as Vahtmäe and Kutseralong havethe stated, inof turbid waters, significant obstacle to the estimation of satellite bathymetry is that the sun glint effect may the optimal bands that are shifted to higher wavelengths, such as the green‐yellow spec‐
This paper compares the derived bathymetric results obtained with three different satellite sensors using three different algorithms

Summary

Introduction

Bathymetry measurements in oceans, rivers, or lakes are essential, especially in coastal areas with intense use of the coastal zone, heavy sea traffic, and vulnerable natural ecosystems. Monitoring of coastal areas is, of great importance to implement sustainable coastal development and ecosystem protection strategies [1,2,3]. High spatiotemporal resolution and a vertical accuracy topographic and bathymetric data are essential for understanding coastal systems evolution [2], and for other environmental applications, such as benthic habitat mapping [4], seabed geomorphology [5], underwater archaeology [6], monitoring of coastal morphological changes, navigation, and fishing [7]

Methods

Results

Discussion

Conclusion