Authors : Giribabu Dandabathula, Omkar Shashikant Ghatage, Subham Roy, Shweta Yadav, Apurba Kumar Bera, Sushil Kumar Srivastav
DOI : 10.1080/01490419.2025.2608329
Volume : 56
Issue : 4
Year : 2025
Page No : 1-31
ICESat-2 ATL24 is a newly released Level-3A bathymetry product providing along-track, refraction-corrected seafloor elevations derived from classified photon returns in shallow coastal waters. This study evaluates ATL24 accuracy against high-resolution multibeam echosounder (MBES) bathymetry at three geographically diverse sites: Mudjimba Island (Australia), Whangaroa Harbor (New Zealand), and Ballyteige Bay (Ireland). Validation was conducted only within the depth range where MBES reference data overlapped with ATL24 retrievals, typically from about −5 m to −25 m. Within this range, ATL24 depths agreed strongly with MBES, with R2 exceeding 0.95 at all sites. The lowest residuals were observed at Ballyteige Bay, where a gently sloping, uniform seafloor yielded an RMSD of 0.34 m. At Mudjimba Island (RMSD = 0.89 m) and Whangaroa Harbor (RMSD = 0.78 m), ATL24 showed reliable bathymetric retrievals even in complex nearshore settings. In shallower waters (from mean sea level to about −5 m), ATL24 provided photon-based depth estimates that could not be quantitatively validated due to the absence of reference data and were interpreted qualitatively. These results demonstrate that ATL24 is a reliable source of shallow-water bathymetry where reference MBES data are available and offers potential for extending mapping coverage into shallow waters where acoustic surveys are limited.