A frontier proposal with a validation plan, not an implemented detector.
Intended capability
Research whether the field could support this proposed outcome: Long-horizon monitoring of structural deflection and settlement: detects mm-scale slab sag, wall lean or facade movement over months, turning every floor into a sparse structural-health sensor between formal inspections.
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 Buildings scene
This is one recorded vertical scenario. It is not separate validation of every capability in the catalog.
01 The physics
Reflection path lengths are set by surface positions: a slab midspan sagging 5mm changes ceiling-bounce path lengths by ~10mm round-trip — ~0.03ns of delay and a measurable phase rotation at 5GHz. Individually tiny, but coherent integration across many links/paths over weeks separates monotonic geometric drift from thermal expansion cycles (which are diurnal and reversible).
02 Shared processing path
CIR sparse recovery with phase-coherent per-path tracking -> compartment Kalman with explicit diurnal-thermal state (removes daily expansion) -> CUSUM on the residual monotonic delay drift over weeks-to-months (119-day drift-control result is the enabling proof) -> NeRF geometry delta to localize which surface moved.
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: mount a large reflective panel on a micrometer stage in a live room, command 1-10mm displacements over days under normal thermal cycling, verify detection threshold; then a loading-dock mezzanine with survey-grade level as ground truth.
04 Commercial hypothesis
For the structural engineer of record / REIT risk officer: 'Post-Surfside assurance: your building's own WiFi watches for millimeter structural movement 24/7 between the five-year inspections.'