Null-field computations of radar cross sections of composite objects

The application of the null-field approach to radar cross section computations for composite objects is reviewed. The scattering problem is solved by means of a determination of the total transition matrix for the composite scatterer. It is noted that alternative approaches are usually available, which lead to different expressions for the transition matrix and which have different numerical characteristics. Results from the numerical implementation of these formulas are illustrated in a number of examples, and it is found that useful convergence can be achieved for a frequency interval that often extends into the resonance region. A number of ways of checking the quality of the results are also indicated