3.2. Site and Mounting Requirements

The measurement area must be free of obstacles, contain no vegetation, be free of rocks, sand deposits, cascades or waterfalls, must not include bridge structures or other fixed elements, and there must be no vegetation or objects between the radar and the water surface, as this can significantly affect measurement accuracy.

The mounting structure used to hold the instrument, such as a pole, bridge railing, or similar support, must be mechanically stable, free of vibrations, and withstand wind and environmental loads. Vibrations can negatively affect measurement stability and accuracy.

Ensure the radar beam is not obstructed.

Waterfalls/cascades must be avoided.

The instrument must be aligned with the direction of water flow. Proper alignment ensures that the radar measures the true surface velocity of the moving water.

The instrument must be aligned with water flow direction.

For optimal measurement accuracy, install the instrument in a section of the river where the flow is uniform and stable. Avoid locations with channel bends or sharp curvatures, tributaries entering the measurement area, sudden widening or narrowing of the channel, and highly turbulent flow. As a general guideline, the minimum distance between the sensor location and any disturbance (such as a tributary, cascade, or channel bend) should be at least four times the width of the river.

Avoid channel sections where the flow is not uniform.

The VX60 uses advanced signal processing and Kalman filtering with physical modeling of water flow. This ensures stable measurements even under turbulent conditions. Moderate surface waviness improves radar signal reflection and measurement quality. In cases of strong turbulence, increased fluctuations in measured values can occur which may result in reduced accuracy of the measurement. If strong turbulence is expected at the monitoring site, it is recommended to set the radar filter length to 60 seconds or higher.