Real-time monitoring of watercourses with VEGA radar transmitters

In 2019, the province of Antwerp decided to develop a structured measurement network for its watercourses. There were many reasons for this step towards IoT. In total, there are currently 65 IoT measuring instruments on the watercourses, 45 of which are the autonomous radar transmitter VEGAPULS Air 41. The measured values from the individual measuring stations are now received in real time on a central data platform, where limit values and automatic alarms can be set separately for each watercourse. In dry periods, the operator can take action in good time and, for example, impose a water withdrawal ban. If, on the other hand, the water level is rising too quickly, the civil protection authorities can be notified at an early stage. 

One of the most important criteria in choosing a suitable measurement solution is the reliability of the generated data. VEGA radar transmitters are used mainly in non-navigable watercourses of category 2. These are small watercourses up to eight metres wide, which are sometimes densely overgrown or located in places that are difficult to access. There are thus many potential causes of interference and incorrect measurement. Besides that, when problems arise, it’s not always easy to take corrective action quickly.

The innovative technology of VEGA radar transmitters has proven to be an excellent solution here. It measures with a small beam angle of just under 8°, so accurate measurement is possible even in very narrow waterways. Another advantage is that VEGAPULS Air 41 is not affected by false echoes and temperature fluctuations. And as there is no blocking distance, i.e. dead band, even sudden and drastic rises in the water level are detected accurately, without the VEGA radar transmitter having to be installed at a particularly high spot.

Yet another advantage of VEGAPULS Air 41 is its Bluetooth function. When carrying out check measurements or adjustment work, maintenance personnel no longer have to lean over the edge of a bridge or stand in the river with waders, workboats or ladders. All they have to do is stand nearby and log in with a smartphone.

For the province of Antwerp, the solution as a whole also had to be compact. The key issue here is the battery capacity and thus the size of the battery pack needed to power the transmitters in remote locations. The VEGA radar transmitter VEGAPULS Air 41 uses LoRaWAN (Long Range Wide Area Network), a wireless technology that enables energy-efficient, long-range communication for the Internet of Things (IoT). This allows it to operate with small batteries and a compact housing – and still provide service for a sufficiently long time. The time it takes before the batteries need to be replaced depends mainly on the time intervals between measurements. The measuring intervals and thus the battery life of VEGAPULS Air 41 can be adjusted to fit the application.

With the IoT solution, the province of Antwerp is on a very good path. Compared to traditional water level measurement, which was complex, costly and, above all, time-consuming, the wireless solution with VEGAPULS Air 41 radar transmitters offers decisive advantages. They provide a reliable and timely warning of low water as well as flooding, allowing countermeasures to be initiated early. The structured measurement network is now to be expanded to at least 100 measuring points.