Updating Sensitivity Maps in Landweber Iteration for Electrical Capacitance Tomography

Y. Li and W. Q. Yang

School of Electrical and Electronic Engineering, The University of Manchester, PO Box 88, Manchester M60 1QD, UK, Email: Yi.Li@postgrad.manchester.ac.uk

ABSTRACT

In electrical capacitance tomography (ECT), a sensitivity matrix is calculated based on high permittivity perturbation with a low permittivity background and a fixed sensitivity matrix is used for both one-step and iterative image reconstruction. This paper presents a new iterative method with the sensitivity matrix updated during the iterative process. Using an updated sensitivity matrix, both the forward and inverse problems can be solved more accurately than using a fixed sensitivity matrix. Some complex distributions, including “sunrise”, cross, T and V shapes, have been examined using an 8-electrode sensor, with both noise-free simulation data and real measurements. The results are promising.

Keywords: ECT, Updating sensitivity maps, Landweber iteration