Use of ICEsat-2 and Sentinel-2 Open Data for the Derivation of Bathymetry in Shallow Waters: Case Studies in Sardinia and in the Venice Lagoon

Abstract

Despite the high accuracy of conventional acoustic hydrographic systems, measurement of the seabed along coastal belts is still a complex problem due to the limitations arising from shallow water. In addition to traditional echo sounders, airborne LiDAR also suffers from high application costs, low efficiency, and limited coverage. On the other hand, remote sensing offers a practical alternative for the extraction of depth information, providing fast, reproducible, low-cost mapping over large areas to optimize and minimize fieldwork. Satellite-derived bathymetry (SDB) techniques have proven to be a promising alternative to supply shallow-water bathymetry data. However, this methodology is still limited since it usually requires in situ observations as control points for multispectral imagery calibration and bathymetric validation. In this context, this paper illustrates the potential for bathymetric derivation conducted entirely from open satellite data, without relying on in situ data collected using traditional methods. The SDB was performed using multispectral images from Sentinel-2 and bathymetric data collected by NASA’s ICESat-2 on two areas of relevant interest. To assess outcomes’ reliability, bathymetries extracted from ICESat-2 and derived from Sentinel-2 were compared with the updated and reliable data from the BathyDataBase of the Italian Hydrographic Institute.

Editorial for Special Issue: “Monitoring Terrestrial Water Resource Using Multiple Satellite Sensors”

“…Jia et al [39] developed a method to obtain a bathymetry map by fusing ICESat-2-derived bathymetry water depth information and Sentinel-2-derived multispectral information via bathymetric empirical models, and achieved an accuracy of about 1m. Bernardis et al [40] also combined ICESat-2 and Sentinel-2 data to map the bathymetry in the Sardinia and Venice Lagoon areas along the coastline, and found their results agreed well with the updated and reliable data from BathyDataBase of the Italian Hydrographic Institute. Cao et al [41] took the flood event in Huoqiu County in 2020 as an example, and integrated ICESat-2-derived water levels and the Sentinel-2-derived flooding extent to estimate the lake storage volumes during the flooding events, showing that it can provide valuable information for flood control and disaster reduction.…”

Monitoring Coastal Waves with ICESat-2

“…ICESat-2 provides a way to measure waves at high spatial resolutions ranging from near-shore to the open ocean. Deep water and open ocean waves have been studied using ICESat-2 data [19][20][21][22] and there has been extensive use of ICESat-2 in coastal zones to extract bathymetry [23][24][25][26][27][28][29][30]. However, there has been no research to date on using ICESat-2 for coastal/near-shore wave measurements.…”