Process tomography system by electrostatic charge carried by particles

Two methods, the back-projection (BP) method and the least-squares (LS) method, were applied to the electrodynamic tomography system. Electrostatic charges were assumed to exist in the sensing zone, and their images were reconstructed using these methods. The reconstructed images were compared with the original ones. The BP method is accurate in detecting the position of the electrostatic charge and is capable of detecting the size of the object. The BP method could not distinguish two charges at separate points in the sensing zone. The LS method could differentiate two points of charge, but the reconstructed images were of poor quality due to the large pixel size. A reconstruction algorithm combining the two methods produced better results.