Nice; Mie scrattering; I was explaining creeping waves with someone recently; cool stuff. I have not done too much with RCS or large structures. I'm mostly RF/Microwave circuits and antennas, though as I move into mmWave, electrically large antennas (both arrays and reflectors) will be come an issue.

Does your code handle lossy dielectrics?

Anyway to instantiate near-field excitation sources on large structures? That's one nice thing about CST; save the near field results from an FEM antenna simulation and instantiate them into a TLM simulation on a large structure.

A a side note, we had a new near field chamber installed, and the guy from Orbit/FR used to run several test ranges. Got on the topic of antenna standards (there really are not any, even standard gain horns). He developed some cylinder standards for scattering. They ship them around the world to verify ranges.