The T-matrix method based on the modified auxilairy-current and null-field methods

Two versions of implementation of the T-matrix method: on the basis of the (i) auxiliary-current and (ii) null-field methods are compared. In both cases, the methods are numerically realized with the use of the discrete-source technique. The scattering patterns of various bodies are calculated by means of both methods with high and approximately equal accuracies, a result confirmed, in particular, through testing the fulfillment of the optical theorem. However, the asymptotics (in the order number) of the scattering pattern coefficients are fundamentally different.