---
plan: 01-03
phase: 01-eskf-core
status: complete
completed: 2026-04-01T21:00:00Z
---

## Summary

Created comprehensive unit test suite for ESKF algorithm and real coordinate chain projection mathematics. All 35 tests pass, covering all six ESKF requirements and full pixel-to-GPS chain validation.

## Key Files Created/Modified

- `tests/test_eskf.py` (290 lines, new) — 18 ESKF tests
- `tests/test_coordinates.py` (420 lines modified, +200) — 17 new projection tests

## Test Coverage

| Category | Count | Requirement |
|----------|-------|-------------|
| ESKF Initialization | 2 | ESKF-04 |
| IMU Prediction | 4 | ESKF-01 |
| VO Update | 3 | ESKF-02 |
| Satellite Update | 3 | ESKF-03 |
| Confidence Tiers | 4 | ESKF-05 |
| Coordinate Chain | 10 | ESKF-06 |
| Integration | 2 | All |

## Commits

- `2e5436a` feat(tests): add comprehensive ESKF + coordinate chain tests (ESKF-01..06)

## Test Results

```
35 passed in 0.36s
```

## Tests by Theme

### ESKF Core Tests (18)
- **Initialization (ESKF-04)**: default init, init_from_gps
- **IMU Prediction (ESKF-01)**: covariance growth, gravity compensation, velocity integration, position propagation
- **VO Updates (ESKF-02)**: uncertainty reduction, position correction, innovation vector
- **Satellite Updates (ESKF-03)**: position correction, covariance tightening, noise-bounded covariance
- **Confidence Tiers (ESKF-05)**: HIGH/MEDIUM/LOW/FAILED states
- **State Access**: ESKFState snapshot
- **Integration**: full fusion sequence

### Coordinate Chain Tests (17)
- **K Matrix (ESKF-06)**: ADTI 20L V1 focal length, custom principal point
- **Camera-Body Rotation**: Rx(180deg) verification
- **Quaternion Rotation**: identity and 90-degree rotations
- **Pixel-to-GPS Chain**: center nadir projection, altitude scaling, off-center offsets
- **GPS-to-Pixel Inverse**: roundtrip accuracy, quaternion rotation handling
- **Transform Points**: cv2.perspectiveTransform identity, translation, empty

## Deviations

None — all acceptance criteria passed.

## Self-Check: PASSED

- [x] 18 ESKF tests covering all requirements
- [x] 17 coordinate chain tests for real projection
- [x] All tests pass with pytest (35/35)
- [x] K matrix builds correctly for ADTI 20L V1
- [x] Center pixel projects to UAV nadir
- [x] Pixel-GPS roundtrip within 1 pixel
- [x] Gravity compensation verified
- [x] Covariance growth/shrinkage validated
- [x] Confidence tier logic tested
- [x] Quaternion rotations working
