Focusing field probe data to image near-field scatterers in three dimensions

Much research has been done recently on the interpretation of measured field probe data in order to locate and quantify error sources present in an antenna range. The author examines an alternative method of analyzing those data by applying spherical phase offsets to focus the field probe data to near-field distances. This technique yields the correct (x,y,z) coordinates of multiple scattering sources deliberately introduced into the simulated data. Data from multiple cuts at arbitrary theta angles are combined to form the three-dimensional image. The author presents an algorithm that takes advantage of symmetries in the polar coordinate system commonly used in field probing to speed the calculations significantly.<>