It's the same thing! What are you trying to do with it? One thing you'll run into is that there isn't a clear frequency response curve for non-visible, so you

It's the same thing! What are you trying to do with it? One thing you'll run into is that there isn't a clear frequency response curve for non-visible, so you need to invent your own frequency to RGB function (false color). Another thing is that radio waves have much longer wavelengths than visible, so diffractive effects tend to be a lot more important, and ray tracing (spectral or otherwise) doesn't do this well. Modeling diffraction is typically done using something like FDTD. https://en.wikipedia.org/wiki/Finite-difference_time-domain_method https://en.wikipedia.org/wiki/Finite-difference_time-domain_...