Highly accurate noncontact water level monitoring using continuous-wave Doppler radar

A novel water level monitoring technique using continuous-wave (CW) Doppler radar is presented. The CW radar works with a DC-coupled baseband that allows accurate monitoring of the slow-varying water level. Ray tracing model has been used to simulate and validate the feasibility of water level monitoring in the presence of ripple. The proposed technique is robust against clutter interference and the fluctuation of water ripples by properly choosing the carrier frequency. Experiment was carried out to monitor the water level in a rain barrel when the water was draining out. Both simulation and experiment shows that the proposed technique can accurately monitor the water level with a high accuracy in millimeter-scale.