gps-denied-onboard/docs/03_tests/47_reprojection_error_spec.md

Acceptance Test: AC-10 - Mean Reprojection Error < 1.0 pixels

Summary

Validate Acceptance Criterion 10: "Mean Reprojection Error (MRE) < 1.0 pixels. The distance, in pixels, between the original pixel location of the object and the re-projected pixel location."

Linked Acceptance Criteria

AC-10: MRE < 1.0 pixels

Test Steps

Step 1: Process Flight with Factor Graph

• Action: Process AD000001-030 through complete pipeline
• Expected Result: Factor graph optimizes full trajectory

Step 2: Calculate Reprojection Errors

• Action: For each matched feature across image pairs:
  • Project 3D point back to image plane using optimized poses
  • Measure pixel distance from original detection
• Expected Result: Array of reprojection errors for all features

Step 3: Compute Mean Reprojection Error

• Action: Calculate mean across all features in all images
• Expected Result: MRE < 1.0 pixels

Step 4: Validate Factor Graph Quality

• Action: Low MRE indicates:
  • Poses geometrically consistent
  • 3D structure accurate
  • No "tension" in factor graph
• Expected Result: MRE correlates with GPS accuracy

Success Criteria

• Mean Reprojection Error < 1.0 pixels
• Standard deviation reasonable (< 2.0 pixels)
• No outlier reprojections (> 10 pixels)

Pass/Fail Criteria

Passes If: MRE < 1.0 pixels Fails If: MRE ≥ 1.0 pixels, indicating geometry inconsistencies