Correlation algorithm for high-precision measurement in FM-CW radar level meters

For the microwave level meter based on the FM-CW radar, we analyze the spec trum correlation of beat signals and propose a measurement algorithm using the fact that there exists a peak in the spectrum correlation of beat signa ls when range difference is sufficiently small. This algorithm can compensa te the nonlinear effect of VCO frequency sweep, making it possible to deter mine the range difference in a precise manner even using a practical VCO. W e present some experimental results to show the validity of this algorithm.