Coastal areas bathymetry based on new hybrid methods and fusion methods of Sentinel-2 and Landsat 8 satellite images

The purpose of this study is to use modern methods to improve the accuracy of depth measurement, first by using the proposed methods based on image fusion of sentinel-2 and Landsat 8 images and then based on hybrid fusion methods. Thus, depth measurements were performed in two studied areas, namely Chabahar Bay and Mousa Estuary, based on different scenarios. These scenarios include the traditional ratio method, the proposed methods based on image fusion using three methods of Intensity-Hue-Saturation, Gram-Schmidt transformation, and Brovey transformation, and the proposed methods based on hybrid image fusion. In order to perform depth measurement based on the proposed hybrid fusion methods, the output of the image transformation using the principal component analysis method was merged with the input image of the best bathymetry map based on image fusion at another level of fusion. Chabahar Bay depth measurement results showed that in comparison with the traditional ratio model, the proposed models based on Brovey and Gram-Schmidt methods and based on a hybrid method resulting from the integration of principal component analysis output and Gram-Schmidt method have the best depth measurement results. Regarding the depth measurement of Mousa estuary, the proposed depth measurement method based on the combination of principal component analysis and Intensity-Hue-Saturation method has created the best result in comparison with the traditional ratio model. Also, the results showed that the appropriateness of the number and distribution of depth field points with the topography of the area has a great effect on the accuracy of depth measurement.