Architecture decision records

A decision is recorded when it closes off an alternative. Each record says what the choice was, what it cost, and what was rejected.

ADR	Decision	Status
ADR-0001	Model the visual anchor as a filter state	accepted
ADR-0002	Use the Joseph form for covariance updates	accepted
ADR-0003	Ship with visual fusion disabled	accepted
ADR-0004	Fix the internal quaternion order and centralise conversion	accepted
ADR-0005	Chi-square innovation gating with per-channel fault isolation	accepted
ADR-0006	NIS window monitor with adaptive covariance inflation	accepted
ADR-0007	Mitigating Spoof Permanence via Hysteresis and NIS Recovery Window	accepted (implementation partial; detection trigger still open)
ADR-0008	The frozen-anchor cross-check is implemented but unreachable	accepted
ADR-0009	Cross-platform numerics and the golden tolerance	accepted
ADR-0010	Determinism and seeding policy	accepted
ADR-0011	CI and supply-chain strategy	accepted
ADR-0012	Every scenario goes through the injection layer	accepted
ADR-0013	Evaluate on recorded IMU data with GNSS simulated from the ground truth	accepted
ADR-0014	IMU white noise enters the process covariance in the textbook form	accepted
ADR-0015	The initial IMU bias sigmas are read	accepted
ADR-0016	TUM VI as a second recorded dataset	accepted
ADR-0017	A stochastic clone for the visual update	accepted
ADR-0018	Honest returns after an outage and the GNSS gate	accepted
ADR-0019	Slow-ramp GNSS spoofing is not detectable with IMU and GNSS alone	accepted
ADR-0020	A second source against a slow-ramp spoof	accepted
ADR-0021	Fault classification from the GNSS innovations	accepted
ADR-0022	A multipath signature on the GNSS innovations	accepted
ADR-0023	The clone against a measured front end	accepted
ADR-0024	The assumed visual noise of the opt-in clone	accepted