An efficient algorithm for computing the coefficients of the characteristic polynomial of 2-D state-space models

For 2-D systems described by a state-space structure, two different methods for computing the coefficients of their characteristic polynomial are introduced. The relative efficiencies of these methods are compared to that of Faddeeva´s method. An efficient method is then chosen which can be used to compute the coefficients of the characteristic polynomial with a minimum number of multiplications.