Width Measurement by Partial Convolution of Radar Signals in Spectral Domain

This work presents a width measurement system that jointly evaluates the signals gathered with two alternately transmitting radar modules that are placed laterally to the object of interest, one on each side. In both radar units, linear frequency-modulated continuous-waves are used as transmit signals. By applying a partial convolution to the resulting intermediate frequency (IF) signals in the spectral domain, the sum of the distances between the radar front ends and the target, and thus the object width is determined in one process step, which significantly reduces the calculation effort compared to individual evaluation of each radar’s data set. Furthermore, the introduced approach allows the use of previously known initial values of the object’s width, which may be used in case of filtering, since a lateral displacement of the target would only affect the individual distance estimates, but not their sum. Simulations as well as measurements in an indoor office environment using two 77GHz radar modules were performed to analyze the applicability and the accuracy of the proposed method.