Frau Alexander mit Driftbojen

A smart drift buoy

Stay in Estonia as part of the Bachelor's thesis

Development and investigation of a sensor package for flow measurement of rivers

At the moment I am working on my bachelor thesis in the course of studies in surveying and geoinformatics in cooperation with the Tallinn University of Technology (TalTech), more precisely in the "center for biorobotics". In a project a sensor package is to be developed, with whose assistance flow measurements in rivers are to be accomplished, in order to improve in this way the computation of water models. The aim here is to develop a system that is as cost-effective as possible. For this reason, a low-cost GNSS sensor was installed in a floating buoy. Exactly this smart drift buoy will be examined for accuracy and suitability in my final thesis, which is supervised by Prof. Dr. Gerrit Austen.

After extensive preparatory work at the HFT, I also had the opportunity to test the buoy for a few weeks in Estonia with the help of financial support from the Friends of the HFT Stuttgart Association and the DVW. From the end of October until the beginning of December I was in Tallinn, the capital of Estonia. One task there was, for example, to connect the GNSS sensor of the buoy with the GNSS reference data service available in Estonia. This makes it possible to determine the position, as well as the direction of movement and speed of the buoy much more accurately. Tests with several buoys were then carried out on a river. The first results are promising, but the data evaluation is still pending at the moment.

During my stay I had the opportunity to get to know Tallinn. The cityscape is very diverse, from medieval buildings from the Hanseatic era to typical Soviet buildings and very modern building complexes. But also the nature does not come too short in Tallinn. Due to the sea, two large lakes and large forest areas, there are many natural recreational areas in the city. Due to the current COVID19 situation, unfortunately not as many activities were possible as would have been possible under normal circumstances.

One experience of Estonia, however, has remained particularly in my memory: In the period from November to December the salmon spawn in the Estonian rivers that are connected to the Baltic Sea. During this period they are not allowed to be fished. For this reason, there has been an initiative here in Estonia for a number of years to carry out patrols to prevent anglers from fishing illegally. The "center for biorobotics" is also involved in these patrols. In this context I was also on one of these tours in the early morning hours. We started in complete darkness with headlamps along the river to the mouth of the sea. There we had a little break and listened to the sound of the sea and saw how it slowly became lighter. The time spent on the beach in the early morning hours radiated an unbelievable calmness...


Kerstin Alexander, Bachelor of Surveying and Geoinformatics

Publish date: 10. December 2020