Non-contact discharge measurement by means of radar technology can be a useful tool for measuring the flow rate of open rivers. This technology works by using a radar sensor to measure the water level of the river and then using that information to calculate the flow rate.

One advantage of using radar technology for non-contact discharge measurement is that it can be used in a wide range of weather conditions, including rain, fog, and snow. Additionally, radar sensors can be placed at a safe distance from the river, which reduces the risk of damage or interference.

To use radar technology for non-contact discharge measurement, a radar sensor is typically placed at a fixed position near the river. The sensor sends out a radar pulse that is reflected off the water surface and back to the sensor. By measuring the time it takes for the pulse to travel to the water surface and back, the sensor can determine the distance from the sensor to the water surface.

By measuring the water level at the same continuously location, the sensor can provide a time series of water level data that can be used to calculate the flow rate of the river. This is typically done using a rating curve, which is a mathematical relationship between the water level and the flow rate of the river.

Overall, non-contact discharge measurement using radar technology can provide a safe, reliable, and accurate method for measuring the flow rate of open rivers. However, it is important to properly install and maintain the radar sensor to ensure accurate measurements. Additionally, it may be necessary to calibrate the sensor periodically to ensure accurate readings.