Image quality measures for wall parameter estimation

Four metrics are examined for measuring image quality in through-the-wall microwave imaging applications. Investigation of these criteria shows that they are likely candidates for use in autofocusing techniques for reducing distortions in through-the-wall images. These distortions occur due to the lack of exact knowledge of the wall thickness and its dielectric constant, which affect the process of coherent active imaging. Using simple images, the results show that the effect of the wall errors on image quality is tolerable for most cases, providing that the errors are fractions of the exact values.