An echo signal processing method without reference curve for guided wave radar level gauge

Both identifying the surface echo and determining best point on the surface echo profile are two key steps in the echo signal processing of guided wave radar level gauge. Some characteristic parameters of the surface echo and main interference echo are compared according to several known levels to identify the surface echo without reference curve. In this step the rising height, decline proportion, width and peak amplitude of the echo are employed in order to process the echo signal. In the second step the middle point of the area of the surface echo is regarded as the best point to reflect the level information. Compared with the common method using the peak point, this method is more suitable for the level measurement of product with low permittivity. The moving clamp simulation and water level measurement experiments are performed to verify the effectiveness of the proposed method.