We consider the problem of construction of nearshore underwater terrain model. While this information is less available, it is the most required for solving various tasks concerning the changes of water level. In the article we show, that it is possible to use the observations of the actual water level changes to obtain the terrain model. We use the freely available satellite images of the resolution of 10 m (in particular Sentinel-2) to observe the shorelines at the subpixel level. As a result we have the shoreline coordinates of higher than 10 m precision. After comparing the shorelines obtained from several overlapping images we have found that the horizontal position of the Sentinel-2 images may have systematic errors of about the size of their pixels, which becomes noticeable for the subpixel processing technique. In the article we suggest a simple algorithm, which allows us to find the horizontal shift vector required to align the contours obtained from two overlapping images. The experimental results show, that after the shift the contours of the shorelines from different images are in good agreement with each other.
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