Applicability of a Recreational-Grade Interferometric Sonar for the Bathymetric Survey and Monitoring of the Drava River. - Ákos Halmai; Alexandra Gradwohl-Valkay; Szabolcs Czigány; Johanna Ficsor; Zoltán Árpád Liptay; Kinga Kiss; Dénes Lóczy; Ervin Pirkhoffer (ISPRS Int. J. Geo Inf., 2020)