Efficient and Fast Method of Wall Parameter Estimation by Using UWB Radar System

Precise SAR imaging of objects or detection of moving a person behind a wall with UWB radar or nondestructive testing of walls in civil engineering requires the knowledge of wall parameters like thickness and permittivity. Their use in the data processing produces more precise and realistic results. The measurement of the wall parameters is challenge in a real environment especially when there is access only from one side of the wall. In this paper, an effective and fast algorithm for wall parameters estimation that can be used in practice is presented. For that purpose the magnitudes and the time positions of reflections from inner and outer interfaces of the wall are extracted from the data. A new scanning method reduces drastically the clutter caused by objects in the measurement environment such as reflections from other walls, the ceiling, the floor and antenna crosstalk. The algorithm was tested on 13 different types of walls with different permittivity and thickness. A handheld M-sequence UWB radar with horn and circular antennas was used for data gathering. The proposed method is very robust and the error of the thickness estimation was less than 10% for most of walls. The whole measurement can be handled by one person. The wall parameter estimation runs in real time and is fully automated.