Role of signal processing for estimating the wall thickness for TWI system

Signal processing is the most recently applicable for microwave signals in Through-Wall Imaging (TWI). It is very important to get acquainted with the wall parameters like its thickness, dielectric constant, propagation time through wall etc. for detection of object behind the wall as well as to know the exact position. The wrong or unknown estimation may result in smearing of the image and displays target away from the actual position behind the dielectric structures (such as buildings). Stepped frequency continuous wave radar (SFCW) with ultra wide band width (UWB, 1-3 GHz)may be used for the detection of an object behind the dielectric wall. An experimental set up is made with various targets located at various distances on the other side of the wall (made of brick and concrete). Inverse Fast Fourier Transform (IFFT) has been applied to convert the frequency domain data obtained into Time Domain and later it is mapped with spatial domain to estimate the wall parameters and also range of the target behind the wall. It is validated that wall thickness remains same with number of observations carried out with various targets at various distance on the other side of the wall also the range of the target is obtained.