Calibration and direction-of-arrival estimation of mm-wave radars: a practical introduction

Abstract

Have you read everything about direction-of-arrival estimation in textbooks but are you still uncertain how to realize it in practice? This tutorial-like paper will help to link the theory with a practical approach for direction-of-arrival estimation using mm-wave radar systems and it deals with arising challenges. Step by step, it is explained how to move from the measured time domain data to the estimated angular position of the target. Since the target angle estimation is usually carried out after range-velocity processing, the required pre-processing steps are described. The assessment criteria to form the relationship between array design and radar performance are expressed with the Rayleigh criterion for angular resolution and the ambiguity function as a measure for the unambiguous angular range. An in-depth instruction on how to carry out the sensor calibration is provided. Besides the choice of a proper calibration object, the required number of measurements and signal-to-noise ratio related issues are considered and supported by measurement results. The discussion of single- and multi-target measurements with the calibrated sensor concludes this work.