The Working Principle and Advantages of Radar Water Level Monitoring Station

The Radar Water Level Monitoring Station mainly uses radar waves to measure the water level height, and its principle is as follows:

The Radar Water Level Monitoring Station is equipped with a radar sensor, which emits high-frequency radar waves (usually in the microwave frequency band) towards the water surface. These radar waves travel at the speed of light and will be reflected when they encounter a target object such as the water surface.

Just as light reflects when it shines on a mirror, radar waves also reflect back when they encounter the "mirror" of the water surface. For example, in a calm lake, when radar waves are vertically emitted to the water surface, there will be a relatively regular reflection.

The monitoring station records the time when the radar waves are emitted and the time when the reflected waves are received. Since the propagation speed of radar waves is known (approximately the speed of light c = 3×10⁸m/s in the air), according to the formula \(d = c\times t/2\) (where d is the distance and t is the round-trip time), the distance from the sensor to the water surface can be calculated.

For example, if the round-trip time of the radar waves is \(t = 2×10^{-6}s\), then the calculated distance \(d=(3×10⁸m/s×2×10^{-6}s)/2 = 300m\). The division by 2 is because the calculated distance is a one-way distance (from the sensor to the water surface), while the measured time is the round-trip time.

After knowing the distance from the sensor to the water surface, combined with the installation height of the sensor (this height is pre-measured and set), the water level height can be calculated.

For example, if the installation height of the sensor is \(H = 5m\) and the calculated distance from the sensor to the water surface is \(d = 3m\), then the water level height \(h = H - d = 5m - 3m = 2m\).

This non-contact measurement method has many advantages. For example, it is not directly affected by factors such as water quality and water flow speed. It can accurately monitor the change of water level in real time and can continuously work under harsh environmental conditions. It is widely used in water level monitoring of rivers, lakes, reservoirs and other water areas.