gps-denied-onboard/_docs/01_solution/decisions/0001-e2e-dataset-strategy.md

ADR 0001 — E2E Validation on Public UAV Datasets

Date: 2026-04-16 Status: Accepted Supersedes: — Superseded by: —

Context

The next_steps.md roadmap (item 3) requires bringing the codebase under the autopilot existing-code flow: build an end-to-end test harness that runs the full product as a black box on real UAV data before further refactoring (VO → cuVSLAM, src/gps_denied/ → src/). Without that harness, any refactor is a blind change — unit tests would stay green while the integrated pipeline could degrade silently.

The obvious data source — a synchronised IMU + downward-camera log from the target tactical fixed-wing UAV — is not available:

• Denys Popov (Mavic) was asked for logs but delivery is open-ended.
• In-house Mavic operators would need to be convinced to perform non-mission flights with nadir-oriented cameras at high altitude, which is not their normal pattern.
• The DJI Mavic flight in /home/yuzviak/Azaion/Data/ has no raw IMU (DJI only exports fused attitude + velocities), so the ESKF path is not exercised.

Blocking the harness until someone flies a mission to spec costs weeks. Meanwhile several mature public UAV datasets exist that ship synchronised camera + IMU + ground truth.

Decision

Build the e2e harness on public UAV datasets as the primary validation substrate. Three datasets, three test tiers:

Tier	Dataset	Role	Platform match
Primary	VPAIR (sample)	Fixed-wing, nadir, 300–400 m — closest to target envelope	Fixed-wing light aircraft ≈ tactical fixed-wing dynamics (constant forward motion, banks)
Stress	MARS-LVIG	Rotary UAV with explicit featureless sequences — stress-test VO on low-texture terrain flagged as CRITICAL RISK in solution_draft02	DJI M300 RTK (rotary) — dynamics mismatch accepted, chosen for the terrain variety
CI regression	EuRoC MH_01	Industry-standard VIO benchmark; every published VIO algorithm reports EuRoC numbers, so harness output can be sanity-checked against literature	Indoor micro-MAV — dynamics mismatch accepted, chosen for reproducibility and paper-comparability

Proprietary data collection remains on the roadmap but is deprioritised to a later phase (see next_steps.md §4). It becomes relevant once (a) we need to validate on our specific airframe's IMU vibration spectrum and camera intrinsics, or (b) VO+ESKF tuning stabilises and we want a "final" dataset captured at our operational envelope.

All adapters share a single DatasetAdapter interface (src/gps_denied/testing/datasets/base.py) with capability flags (has_raw_imu, has_rtk_gt, has_loop_closures, platform_class), so integration tests auto-skip paths the current adapter can't exercise rather than failing them.

Consequences

Positive:

• Harness and refactor work unblocked on day one — no person-dependent delay.
• Three datasets cover three distinct failure modes: fixed-wing dynamics (VPAIR), low-texture terrain (MARS-LVIG featureless), indoor benchmark comparability (EuRoC).
• Public numbers for EuRoC mean we can cross-check our ATE against OpenVINS / VINS-Fusion — catches gross regressions immediately.
• Capability-flag pattern means an adapter that ships poses but not raw IMU (VPAIR) still contributes: VO+GPR+graph paths run, ESKF path is explicitly skipped.

Negative / accepted trade-offs:

• VPAIR and MARS-LVIG are academic-use-only licences. Fine for R&D and internal CI, not for shipping benchmarks in commercial material. ALTO (BSD-3) is the escape hatch if commercial-license benchmarks become a requirement.
• VPAIR sample has no raw IMU — full ESKF+VO path is not exercised by it. EuRoC and MARS-LVIG cover that gap.
• Altitude envelope of public datasets (indoor EuRoC, 80–130 m MARS-LVIG, 300–400 m VPAIR) undershoots the target 200–1500 m tactical envelope. Extrapolating upward is a leap of faith; real-target-altitude validation stays on the roadmap.
• Dataset formats vary wildly (EuRoC ASL, VPAIR ECEF+Euler text, MARS-LVIG ROS bags). Each adapter is custom. Mitigation: shared coord.py helpers (ECEF→WGS84, Euler→quaternion) and a small design contract enforced by the ABC.

First real-run evidence (VPAIR sample, 2026-04-16): pipeline completes on 200 fixed-wing nadir frames without crashing, but ATE RMSE ~1770 km — VO alone diverges catastrophically without IMU or satellite anchoring. This is the baseline. Expected improvement comes from EuRoC (has raw IMU → ESKF path works) and from tuning VO+GPR for high-altitude nadir imagery.

Alternatives considered

• Wait for Denys / internal pilots to collect data. Rejected: unbounded delay, no guarantee of raw IMU, coordinates nothing we can start on today.
• Use only EuRoC. Rejected: indoor micro-MAV dynamics are nothing like a tactical fixed-wing, and it has no place-recognition-against-satellite angle. Good for CI, insufficient for primary validation.
• Preprocess datasets into a single normalised format and load via one reader. Rejected on YAGNI — three adapters with a shared ABC stay clearer than a converter pipeline and don't lose dataset-specific metadata.
• Use Mid-Air (synthetic). Rejected: synthetic extremely-low-altitude quadcopter flights. Adds no signal over SyntheticAdapter which we already have for harness self-test.

References

• Roadmap context: next_steps.md §3
• Harness architecture: src/gps_denied/testing/README.md
• Target system: _docs/01_solution/solution.md, §Testing Strategy
• Low-texture CRITICAL RISK: _docs/01_solution/solution_draft02.md
• Local working drafts (not in repo): .planning/brainstorms/2026-04-16-e2e-datasets-design.md, .planning/brainstorms/2026-04-16-e2e-datasets-plan.md