Fig. 1. Flow chart of proposed method

Fig. 2. Schematic structure of the physical radiative transfer CNN model

Fig. 3. Extraction results of seafloor points from ICESat-2

Fig. 4. Comparison between the proposed method and the standard DBSCAN

Fig. 5. Error of ICESat-2 reference bathymetric point depths vs. in situ depths in St. Croix

Fig. 6. Accuracy evaluation result

Fig. 7. Results of this method in different sites

Fig. 8. Bathymetric map obtained from Combination 1 in St. Croix

Fig. 9. Comparison of accuracy of different band combinations in St. Croix

Fig. 10. Accuracy evaluation result without atmospheric correction

Fig. 11. Accuracy evaluation result without K_d

Fig. 12. Error of ICESat-2 reference bathymetric point depths vs. estimated depths