Is the process of collecting data about the depths (bathymetry) in the study area. Performed with the help of special technical devices depends on circumstances and also can be performed manually (see - Tools and methods of bathymetric surveying). An Echo Sounder attached to the transducer, filters and records the time cycle of pulse. At the same time with pulse recording, a GPS device can record the location reading for each pulse. Once all the data has been taken, adjustments are made on the basis of fluctuations in the level of the water surface, which may occur during surveying process. Individual points could be easily mapped into a GIS. After the necessary processing, bathymetric survey results represent an array of geo-referenced data, which contains information on the spatial distribution of depths in the survey area.
Depending on the coordinate system selected, each point represented with a set of three (3) values:
• BLZ (Latitude, Longitude, depth) or
• XYZ (latitude and longitude, depending on the chosen projection; depth)
In the future, bathymetric data could be used for general analysis of the bottom topography and mapping or solving applied problems (sediment accumulation analysis, control of dredging operations and etc.).