Indian Railways
The HydroSurveyor-M9 system from SonTek, a Xylem brand, is an instrument/technology that Indian Railway has employed to rapidly measure bathymetry data along with velocity data. The HydroSurveyor is a multi-frequency acoustic Doppler current profiling system (ADCP) equipped with nine acoustic beams, five of which are used to survey at any one time; four slanted beams provide a velocity profile from up to 128 cells as well as measure depth, and then there is a vertical beam with an 80m range which measures the depth directly below the system.
