A frontier proposal with a validation plan, not an implemented detector.
Intended capability
Research whether the field could support this proposed outcome: A doorway that notices when a person walks through carrying a large concealed conductor — crowbar, machete, long gun, pry bar — and raises the risk score of the approach event. Not airport-grade classification; a physics-based 'metal anomaly on entry' flag.
This describes the intended outcome. Readiness is research concept, evidence is class C, and a catalog mapping or recording is not proof of this outcome at a real site.
Solution blueprint
See the environment before installing it.
This exact kit is one of 191 first-class designs. It includes geometry, objects, nodes, wording, scenarios, installation, limitations, and catalog-bound readiness.
No rendered revision is available yet.
Bundled recording
A related Home scene
This is one recorded vertical scenario. It is not separate validation of every capability in the catalog.
01 The physics
Metal is a near-perfect scatterer (sigma -> infinity) with radar cross-section far exceeding tissue per unit area; a 60 cm steel bar carried against a body adds specular returns and polarization/multipath changes that a body-only crossing does not produce. The residual between the observed field and the reconstructed 'human-only' field carries the conductor's signature.
02 Shared processing path
RFF/NeRF field reconstruction (stage 5) fits eps_r/sigma of the portal scene per crossing -> subtract enrolled human-crossing manifold (stage 3) -> excess-sigma residual localized on the body -> fused with gait fingerprint (stage 2) for stranger+metal compound alerts.
This is a capability design path. Components may be shared with other catalog entries; it is not presented as a unique algorithm.
03 Validation plan
Own-hardware portal rig: 6-node doorway mesh, 15 subjects x {nothing, laptop, frying pan, crowbar, mock long-arm} x 20 crossings, report detection AUC vs conductor size and body-position; no suitable public dataset exists.
04 Commercial hypothesis
"The front door that whispers 'he's carrying something long and metal' to your monitoring center." For gated-community guardhouses and high-end residential security integrators.