TERMINATION CRITERIA IN ITERATIVE SOLUTION OF LARGE SCATTERING PROBLEMS USING INTEGRAL-EQUATION METHODS

Iterative methods are used increasingly for solution of the extremely large matrix equations generated by integral equation analysis of mult i-wavelength frequency domain scattering. Although much cheaper than d irect methods, the matrix solution remains the dominant cost, and is v ery costly. The criterion adopted for termination of the iteration can have a marked effect on this cost. We show that for large scattering problems a robust and rational prior choice of termination criterion c an be made, based only on discretization. This allows confident use of a much larger termination residual than those commonly used, with con sequent cost reduction.