Lane C · the measurement engine
Every coherent Arden instrument — a satellite, a ground FMCW radar, a two-ear SDR — measures a partial region of the same scene's k-space. The ESP32 mesh joins on a different observable — which emitters occupy which carriers in a room, not the scene's k-space. The operators stay different per band, but they share one standard. A rung is a physical capability; a product is a readout of one.
PHYSICS-FIRST TAXONOMY LIVE · GROUPED A–E RUNGS
Ratified 2026-08-06. The old linear R0–R7 list is retired: it let a product masquerade as a rung. Rungs are now organized by the physical information the measured field carries.Operating contract
The bistatic spine covers a satellite, a ground FMCW radar and a WiFi-CSI link with no special cases. But WiFi CSI, SAR and mmWave are different regimes — so each operator declares the band, field and bandwidth it holds in, and refuses outside it. Never a plausible wrong number.
Every claim carries its evidence tier and its refusal. A single collect resolves two k-axes and refuses the third, with the numbers attached. Provenance is asserted, never inferred — an undeclared tier is a loud error, not a silent guess.
A rung ships with the negative control that could have failed it — a false-cluster rate, a held-out residual, a two-derivation cross-check — or it does not ship. Breathing is not a rung; it is one frequency read off the motion-spectroscopy operator.
§ 01 — the capability rungs
Showing 12 of 12 rungs
Constants with one home, the honesty contract, the k-space spine, geodesy and metrology — the vocabulary every other rung is written in.
gate speed-of-light defined once (anti-fork gate); provenance tiers loud on the undeclared.
Which k-axes an aperture resolves and which it refuses. A geometric rank test that gives the same verdict at any sampling density — and runs on real 55k-pulse collects, not just fixtures.
gate sampling-independence regression + 55k-pulse real-scale run · two independent derivations of the layover normal agree to 2.4e−6°.
Backprojection, PGA autofocus, motion compensation, dual-apodization / SVA, phase unwrap, accumulation and registration — phase history to a focused, provenance-tagged image.
gate held-out operator residual; SVA sidelobe suppression vs. textbook; forward·adjoint consistency.
Each operator declares the band, field (far / near), fractional bandwidth and geometry it holds in, and refuses outside it — the axis mmWave short-range breaks. Plus the FMCW cold-start warm-up that refuses range until the timing zero settles.
gate a SAR operator refuses a WiFi-CSI measurement; a far-field operator refuses a mmWave near-field geometry; every regime refusal holds.
Radial velocity, micro-Doppler, and periodic and aperiodic motion — one operator that recovers the scatterers' motion spectrum and refuses on noise.
readouts breathing · heartbeat · gait cadence · machinery vibration · blade-flash · velocity — not rungs
gate recover a known injected rate (±2 BPM) and refuse an empty scene; a hard refusal floor under motion clutter.
Coherent change detection, InSAR-style deformation, presence-by-change, and the speckle statistics that calibrate a detection's false-alarm rate.
gate the negative control — disjoint / duplicate epochs must refuse to signal change, and the refusal must hold.
Polarimetric decomposition, material / dielectric, target type — the axis the old roadmap had no rung for. Polarization is a first-class EM observable; the operator can be built and negative-controlled on synthetic and Umbra VV data like every other rung.
gate known-material recovery + the negation — isotropic / depolarized clutter must not be assigned a class.
Carrier-frequency-invariant device fingerprints, receiver-portability, and unsupervised clustering in clutter — which emitter, never a fabricated where.
gate replay reproducibility + zero false clusters on a verified quiet band. The real cluttered-IQ benchmark (#31) is data-blocked pending the ESP32 beacon fleet.
The evidence ladder plus a second, third-party-origin axis; refusal semantics; the display class that keeps a suppression product out of the coherent chain.
gate an undeclared or misspelt tier is a loud UndeclaredEvidenceTier, never a silent below-floor rung.
Union-takes-weaker where senses share ground; multistatic k-fill (two grazing angles resolve the refused third axis). The open half is cross-band fusion — a CSI + FMCW + SAR view of one scene into one honest claim. It buys more about the scene, never finer detail of it.
gate disjoint footprints refuse to fuse; two coplanar looks still refuse the layover normal; the cross-band wall forbids phase-adding X-band to 2.4 GHz.
Physics-reconstructed (adjoint / forward model, detail only from the measurements) vs. prior-reconstructed (a prior filled detail beyond the PSF) — two axes on one field, each badged so invented detail never launders into measured.
gate consistency, not correctness — a reconstruction must never beat the support that constrains it.
A measurement-native foundation model and learned estimation — inverting the known forward model, output kept consistent with the measured samples. Estimation, not SAR→optical translation.
gate must beat a classical baseline at equal residual; a 7-control negative battery with counterfactual ablation as the killer test.
Breathing is not a rung. It is one frequency read off the motion-spectroscopy operator — the same one that gives heartbeat, gait, vibration and velocity.