Abstract
Satellite-derived bathymetry (SDB) is the process of estimating water depth in shallow coastal and inland waters using satellite imagery. Recent advances in technology and data processing have led to improvements in the accuracy and availability of SDB. The increased availability of free optical satellite sensors, such as Landsat missions and Sentinel 2 satellites, has increased the quantity and frequency of SDB research and mapping efforts. In addition, machine learning (ML)- and deep learning (DL)-based algorithms, which can learn to identify features that are indicative of water depth, such as color or texture variations, have started to be used for extracting bathymetry information from satellite imagery. This study aims to produce an initial optical image-based SBD map of Horseshoe Island’s shallow coasts and to perform a comprehensive and comparative evaluation with Landsat 8 and Sentinel 2 satellite images. Our research considers the performance of empirical SDB models (classical, ML-based, and DL-based) and the effects of the atmospheric correction methods ACOLITE, iCOR, and ATCOR. For all band combinations and depth intervals, the ML-based random forest and XGBoost models delivered the highest performance and best fitting ability by achieving the lowest error with MAEs smaller than 1 m up to 10 m depth and a maximum correlation of R2 around 0.80. These models are followed by the DL-based ANN and CNN models. Nonetheless, the non-linearity of the reflectance–depth connection was significantly reduced by the ML-based models. Furthermore, Landsat 8 showed better performance for 10–20 m depth intervals and in the entire range of (0–20 m), while Sentinel 2 was slightly better up to 10 m depth intervals. Lastly, ACOLITE, iCOR, and ATCOR provided reliable and consistent results for SDB, where ACOLITE provided the highest automation.
Original language | English |
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Article number | 2568 |
Journal | Remote Sensing |
Volume | 15 |
Issue number | 10 |
DOIs | |
Publication status | Published - May 2023 |
Bibliographical note
Publisher Copyright:© 2023 by the authors.
Funding
This study was carried out under the auspices of the Presidency of the Republic of Türkiye, supported by the Ministry of Industry and Technology, and coordinated by the TUBITAK MAM Polar Research Institute. The authors would like to thank the Turkish Naval Forces Office of Navigation, Hydrography and Oceanography (ONHO) for providing the bathymetry data. This study was funded by the Scientific and Technological Research Council of Turkey (TUBITAK), 1001 program, Project No: 121Y366.
Funders | Funder number |
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Ministry of Industry and Technology | |
Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | 121Y366 |
Keywords
- atmospheric correction
- deep learning
- Landsat 8
- machine learning
- satellite-derived bathymetry
- Sentinel 2