Develop a Huygens-based feed-horn propagation model

Develop a physically grounded simulation of electromagnetic-field propagation through the feed horns using Huygens’ principle, replacing the fallback procedure that combines the electric fields at the feed-horn entrance into a single output field.

Background

The camera simulation represents each feed horn by multiple Huygens scatter centers at its entrance opening. To obtain the field at the antenna behind a feed horn, the authors ideally seek to propagate the fields through the actual feed-horn geometry, including the effects of field combination, geometric gain, and possible Fresnel-reflection losses.

The presented work instead uses an approximation that combines the squared magnitudes of the input electric fields and takes a square root, thereby preserving total energy but not explicitly modeling propagation through the feed-horn structure. A full Huygens-based feed-horn simulation remains unresolved.

References

Ideally, one would simulate the propagation of the electric fields through the feed horn based on the geometry of the feed horn. However, we failed to simulate the feed horn using Huygen's principle.

— Simulating an imaging atmospheric radio telescope to observe cosmic gamma rays and cosmic neutrinos  (2608.25962 - Mueller et al., 26 Aug 2026) in Section 4, subsection “Combining the scatter centers of a feed horn” (label SecSimulatingTheFeedHorn)