Radar concepts for inline non-destructive testing

Radar-based sensors have been for a long time an integral part of detection threads over a long distance, even under harsh environmental conditions. The availability of compact radar sensors and the development of increasingly cost-effective radar sensors make the technology interesting for industrial applications. The focus was initially on developments requiring a moderate measurement speed, such as level sensors for silos. However, radar sensors offer several advantages, making them suitable for a whole spectrum of metrological tasks. This includes the ability to measure the distance to surfaces with μm resolution, to know how to screen non-electrically conductive materials, to be able to carry out several thousand measurements per second or to be able to generate high-resolution 2D or 3D images. This paper aims to shed light on the various aspects of the use of radar systems for industrial applications.