Underwater hyperspectral imagery for Posidonia oceanica mapping: challenges and preliminary results from the POSEIDON Project - Longhi, V.; Grasso, N.; Maschio, P. F.; Menna, F.; Pansini, A.; Lingua, A. M.; Chiabrando, F.; Nocerino, E.; Ceccherelli, G.; Rossi, S. (Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., 2025)