Geo-matching | Your Product Platform for Surveying, Positioning and Machine Guidance Join Geo-matching now!

Echo Sounders for Hydrographic Surveying

Echo sounding is measuring the depths using sound. The echo sounder has been around for over a 100 years in hydrographic surveying and is still the most often used for collecting bathymetry. Other options could be with light (bathymetric LIDAR, satellite derived bathymetry). The operating method of an echo sounder is quite simple in its basic form. The echo sounder emits a sound pulse which is transmitted by a transducer to the bottom. The pulse reflects off the bottom and is received by the transducer. The so-called Two Way Traveltime (TWT) is now divided by two and multiplied by the speed the signal has travelled with through the water. By adding the draught of the transducer the depth of the bottom relative to the water surface is known. By adding the tidal value at the time of measurement (or an accurate GNSS height) the depth relative to some vertical or chart datum can be found.

Read more