Removing the wall effects using electromagnetic complex coating layer for ultra-wideband through wall imaging

The wall-effect compensation is one of the most annoying steps in modern through wall imaging (TWI) problems. Presence of wall not only increases the computational burden due to clutter rejection and complex imaging algorithms, but also blurs the reconstructed image. To mitigate this drawback, different wall-clutter rejection methods have been subject of numerous researches in recent years. However, these wall-clutter rejection methods mainly focus on removing the first strong reflection of wall. In this study, a novel wall-removal method (not only wall-clutter rejection) based on transformation optics (TO) is addressed. This is the first time that TO has been applied to TWI problem. Using this new method, TWI is cast to a free space imaging problem which is computationally more effective and results in more focused images. Real-time imaging is also more available in this case. Without loss of generality, a two-dimensional TWI configuration is assumed to evaluate the provided technique. A single point-like scatterer hidden behind a wall is used to obtain the imaging system point spread function resulted by the proposed technique. Finally, it is shown that the presented method is valid even for lossy walls. Reconstructed images show satisfactory focusing that highlight the capabilities of presented method.