gps-denied-onboard/_docs/00_research/06_component_fit_matrix.md

Component Fit Matrix

Top-Level Matrix

Component Area	Candidate	Pinned Mode/Config	Option Family	Intended Role	API Capability Evidence	Mismatches / Disqualifiers	Status	Decision Rationale
Calibration / geometry	OpenCV 4.x	C++/Python calibration, undistortion, RANSAC homography, reprojection-error measurement	Established production / open-source	Camera intrinsics, image normalization, VO/satellite homography verification	MVE: 02_fact_cards.md OpenCV block; Source #5	None	Selected	Exact API fit and permissive utility role.
VO / IMU propagation	BASALT + project-owned safety/anchor wrapper	BASALT VIO consumes calibrated nav-camera frames + FC IMU; wrapper fuses satellite anchors, calibrates uncertainty, emits source labels and GPS_INPUT semantics	Open-source production candidate	Relative VIO state, completion/error benchmark, wrapped covariance/confidence, degraded modes, GPS_INPUT semantics	Sources #33-#35; Facts #37, #40, #41	BASALT covariance/confidence must be calibrated in wrapper; no special nadir mode	Selected	User-selected best production trade-off: permissive licensing and stronger benchmark/completion evidence than OpenVINS/Kimera, with wrapper covering project-specific safety semantics.
VO / VIO reference	OpenVINS	Monocular camera + IMU EKF/MSCKF reference runs with covariance extraction	Open-source research	Benchmark and covariance reference	Sources #3, #27, #28, #35, #38; Facts #4, #30, #38	GPL-3 production dependency risk; completion/divergence risk on some sequences; does not own satellite anchor / GPS_INPUT / blackout / cache-write state machine	Reference only	Best covariance baseline, but not selected as shipped production dependency.
VO / VIO backup	Kimera-VIO	Mono/stereo camera + IMU VIO/SLAM backup candidate	Open-source production candidate / fallback	Alternative VIO baseline	Sources #34, #36; Fact #39	Heavier/stereo-oriented; mono-inertial path has documented parameter caveats	Backup candidate	BSD-friendly backup if BASALT fails project replay/runtime gates.
VO / SLAM alternative	ORB-SLAM3	Monocular-inertial SLAM	Open-source research	Benchmark and failure-mode comparison	Source #4, Fact #5	GPLv3; heavier SLAM/map lifecycle than required	Rejected	Does not fit licensing/scope for production.
VPR descriptors	DINOv2-VLAD / AnyLoc-style	Precomputed satellite chunk descriptors; conditional query descriptor on relocalization triggers; TensorRT path only after embedding-fidelity check	Current SOTA / research	Global top-K candidate retrieval	Sources #7, #8, #21, #22, #30, #32; Facts #10, #11, #24, #33, #34, #36	Runtime and embedding-fidelity gates on Jetson; model-size/index-size selection required	Selected with runtime gate	Best evidence for change-robust VPR, but not per-frame and not blindly TensorRT-converted.
Vector retrieval	FAISS	CPU-first aarch64 index; saved/loaded index over float/PQ descriptors; GPU only if custom Jetson build is proven	Established production / open-source	Top-K candidate chunk search	MVE: 02_fact_cards.md FAISS block; Sources #9, #25	GPU FAISS not default on Jetson ARM64	Selected	Exact top-K descriptor retrieval fit with CPU-first deployment.
Local matching	LightGlue + DISK/ALIKED	CUDA/ONNX-profiled DISK or ALIKED feature extraction + LightGlue matching on bounded top-K candidates	Current SOTA / open-source	2D-2D correspondences for RANSAC and MRE	MVE: 02_fact_cards.md LightGlue block; Sources #6, #23, #31	Runtime quality gate; extractor choice must avoid SuperPoint license issue	Selected with runtime gate	Exact input/output fit with deployable licensing path; ALIKED/LightGlue is preferred for anchor verification.
Local matching fallback	SuperPoint + LightGlue	SuperPoint features + LightGlue	Current SOTA / license-gated	Optional benchmark/fallback	Source #6	SuperPoint restrictive license	Needs user decision	Do not use as default production dependency without legal review.
Cache imagery	COG + manifest/sidecar	Tiled compressed GeoTIFF tile objects with CRS, capture date, source, m/px, freshness, descriptor sidecars; write-new-object lifecycle	Established geospatial format	Immutable service tiles and generated candidate tiles	Source #18, Facts #21, #29	No in-place mutation; manifest manages active tile version	Selected	Fits geospatial raster access and write-new-tile workflow.
Cache packaging	PMTiles	Read-only tile archive	Established web-map archive	Optional export/snapshot	Source #17, Fact #20	Cannot update in place	Rejected for live cache	In-flight tile generation needs mutable write-new objects.
MAVLink	MAVSDK + pymavlink	MAVSDK telemetry subscriptions; pymavlink/raw MAVLink GPS_INPUT emission to ArduPilot GPS1_TYPE=14; velocity source/ignore-flag behavior SITL-tested	Established APIs	FC telemetry, QGC status, GPS substitute output	MVE: 02_fact_cards.md MAVSDK/pymavlink block; Sources #10-#12, #24	Plane SITL behavior and velocity-source parameters must be validated	Selected	Exact output contract with known ArduPilot pitfall covered.
Validation	EuRoC + AerialVL/VPAir + Plane SITL + representative flight	Layered validation suite	Test strategy	Prove ACs before production	Sources #19, #20	Public data not sufficient for final proof	Selected	Covers component de-risking plus final representative proof.

Restrictions Cross-Check — Selected Production Architecture

Restriction	Candidate-mode behavior	Result	Evidence
Fixed-wing only	Architecture assumes forward motion, rare sharp turns, no hover dependency.	Pass	Problem context; Source #1
Fixed nadir nav camera	VO/orthorectification uses fixed camera extrinsics; attitude compensation from FC.	Pass	Source #5
Operational area / flat terrain	Flat terrain assumption supported; repetitive agricultural terrain handled as validation class and confidence risk.	Pass	Source #2
Weather/season classes	Validation matrix includes seasonal/visibility classes.	Pass	05_validation_log.md
Two-camera split	Nav camera drives localization; AI camera object localization uses current GPS-denied state and AI gimbal/zoom.	Pass	AC-7.1/7.2
Satellite Service offline boundary	Runtime uses local COG/cache + FAISS descriptors only; no in-flight provider fetch.	Pass	Sources #17, #18
Freshness gates	Tile manifest carries capture date and sector; stale tiles rejected/down-weighted.	Pass	AC-8.2, AC-NEW-6
Jetson Orin Nano Super	Hot path is lightweight; heavy VPR conditional; runtime profiling gate required.	Pass	Sources #15, #16
MAVLink / ArduPilot only	MAVSDK telemetry + pymavlink GPS_INPUT, GPS1_TYPE=14.	Pass	Sources #10-#12
No raw frame storage	FDR keeps estimates, telemetry, tiles, and low-rate failure thumbnails only.	Pass	AC-8.5, AC-NEW-3

AC Cross-Check — Selected Production Architecture

AC	Candidate-mode behavior	Result	Evidence
AC-1.1	Satellite anchors and ESKF output target <=50 m for >=80% normal frames.	Pass	Facts #1, #2
AC-1.2	Same pipeline targets <=20 m for >=50% normal frames; validated statistically.	Pass	05_validation_log.md
AC-1.3	ESKF tracks anchor age and covariance; VO-only and IMU-fused drift measured between anchors.	Pass	Fact #1
AC-1.4	ESKF emits covariance; telemetry/FDR carries source label.	Pass	Fact #16
AC-2.1a	VO hot path handles normal overlapping frames; failures trigger mode change.	Pass	Facts #1, #6
AC-2.1b	Satellite anchor success measured separately through VPR + local match + RANSAC.	Pass	Facts #2, #7, #12
AC-2.2	OpenCV/LightGlue provide correspondences and homography MRE measurement.	Pass	Facts #6, #7
AC-3.1	ESKF innovation gates reject outliers; covariance grows instead of trusting jumps.	Pass	Reasoning chain
AC-3.2	Sharp turn VO failure triggers VPR relocalization.	Pass	AC design; Source #2
AC-3.3	Disconnected segment handled by global retrieval and pose-graph/ESKF re-anchor.	Pass	Source #2
AC-3.4	Loss counter and timer trigger GCS relocalization request while dead reckoning continues.	Pass	AC design
AC-3.5	Image-quality/blackout state switches to IMU-only and rejects spoofed GPS.	Pass	AC design; Facts #16, #17
AC-4.1	Heavy VPR is conditional; steady-state path is VO/IMU. Jetson profiling is a runtime quality gate.	Pass	Facts #3, #18
AC-4.2	Descriptor/index memory is budgeted; FAISS and cache are precomputed/pruned.	Pass	Facts #12, #13
AC-4.3	GPS_INPUT emitted by pymavlink; ODOMETRY remains disabled in v1.	Pass	Facts #14-#16
AC-4.4	Estimator emits frame-by-frame; no batching required.	Pass	Architecture
AC-4.5	Corrections are emitted as updated estimates with timestamps and covariance.	Pass	Architecture
AC-5.1	Startup initializes from last trusted FC state plus IMU propagation.	Pass	Architecture
AC-5.2	>3 s no-estimate path enters degraded/failsafe behavior; Plane SITL proves FC response.	Pass	Fact #17
AC-5.3	Cold restart uses FC state and preloaded cache/index.	Pass	AC-NEW-1
AC-6.1	QGC receives downsampled status; FDR keeps high-rate details.	Pass	MAVSDK telemetry + FDR design
AC-6.2	Command ingress reserved through MAVLink status/named values/custom dialect.	Pass	MAVLink design
AC-6.3	GPS_INPUT lat/lon is WGS84.	Pass	Fact #16
AC-7.1	Object localization exposes level-flight accuracy and maneuver bound.	Pass	Geometry design
AC-7.2	Flat-terrain trig projection from UAV GPS + gimbal/zoom/altitude.	Pass	Geometry design
AC-8.1	Cache contract requires 0.3-0.5 m/px imagery.	Pass	Restrictions
AC-8.2	Freshness metadata gates anchors.	Pass	Restrictions
AC-8.3	Precomputed descriptors and FAISS index are part of cache budget.	Pass	Facts #10, #12, #13
AC-8.4	Generated tiles are new COGs with quality metadata for Service ingest.	Pass	Fact #21
AC-8.5	Raw frames are not retained.	Pass	FDR design
AC-8.6	VPR chunks use overlap/multi-scale descriptors and dynamic K.	Pass	Facts #2, #12
AC-NEW-1	Engines/indexes built before flight; first fix benchmark validates <30 s.	Pass	Runtime plan
AC-NEW-2	Plane SITL verifies spoofing trigger and promotion <3 s.	Pass	Fact #17
AC-NEW-3	FDR segment rollover validates <=64 GB.	Pass	Validation plan
AC-NEW-4	Mahalanobis gates and calibrated covariance target false-position budget.	Pass	ESKF design
AC-NEW-5	Thermal profiling at 25 W validates no throttle.	Pass	Facts #18, #19
AC-NEW-6	Tile age rejection/down-weighting built into anchor gate.	Pass	AC design
AC-NEW-7	Tile writes require parent-pose covariance and sidecar metadata; Satellite Service voting is external contract.	Pass	AC design
AC-NEW-8	Dead-reckoned blackout mode degrades GPS_INPUT fields at covariance thresholds.	Pass	Facts #16, #17

Decision Rules Applied

• No GPL VIO/SLAM library is selected as a production dependency.
• Runtime gates are classified as runtime-quality validation gates, not API capability blockers.
• Every selected component has an exact input/output role and a validation path.
• Any candidate with license uncertainty is marked Needs user decision or non-production.

Mode B Revisions Applied

• FAISS pinned mode changed to CPU-first on Jetson ARM64.
• DINOv2 TensorRT path requires descriptor-fidelity validation against PyTorch/ONNX.
• GPS_INPUT tests now include velocity-source and ignore-flag behavior.
• COG cache lifecycle clarified as write-new-object plus manifest versioning, not in-place mutation.
• Visual/satellite security controls now include signed manifests, cache provenance, stale-tile rejection, and multi-signal consistency checks.

Mode B Round 2 Revisions Applied

• OpenVINS is explicitly better than naive OpenCV-only VIO, but remains reference-only because the shipped estimator must own source labels, covariance gates, spoofing/blackout states, cache-write eligibility, and MAVLink semantics.
• The selected VO wording is now "OpenCV geometry + project-owned ESKF" to avoid implying a fragile OpenCV-only odometry implementation.
• DINOv2-VLAD + CPU-first FAISS + ALIKED/LightGlue remains selected for satellite retrieval and anchor verification, with retrieval limited to relocalization triggers and bounded top-K verification.
• SIFT/ORB remains a regression/fallback baseline; SuperPoint remains non-production until legal approval.

Mode B Round 3 Revisions Applied

• BASALT is selected as the production VIO candidate.
• OpenVINS remains the covariance/reference baseline, not a shipped dependency by default.
• Kimera-VIO remains a backup VIO candidate because its license is production-friendly but mono-inertial caveats make it weaker for the single-nadir-camera path.
• The project-owned safety/anchor wrapper remains mandatory around BASALT for satellite anchor acceptance, source labels, blackout/spoofing modes, cache-write eligibility, calibrated confidence, and MAVLink GPS_INPUT.