First-hand information for everyone
Two independently built event‑camera systems were compared on the SPARK 2026 benchmark for 6‑DoF spacecraft pose estimation. The direct‑regression network predicts translation and rotation in one pass, using a global voxel for translation, a cropped view for rotation, and a physics‑motivated scale cue. The modular pipeline first detects 2‑D keypoints with HRNet, adapts the model with CycleGAN and DANN, pulls the pose with EPnP+RANSAC, and smooths it over time with an EKF. In the hidden‑test protocol the direct system achieved a relative translation error of 0.1335 m, an orientation error of 0.9101 rad, a composite score of 1.0436, and full 100 % coverage. The modular system achieved a lower translation error of 0.0285 m but a higher orientation error of 1.1767 rad, a composite score of 1.2052, and also 100 % coverage. These numbers illustrate a component‑wise reversal: direct regression reduces orientation error by 22.7 % while modular processing reduces translation error by 78.7 %. Because the benchmark adds a unitless translation error to a radian rotation, the ranking is dominated by orientation, explaining why the direct system tops the leaderboard despite its larger position error. The results motivate a hybrid design that would couple direct orientation estimation with geometry‑constrained translation recovery.

| System | Configuration | Cov. | ER↓ | ET↓ | EP↓ |
|---|---|---|---|---|---|
| Published SPADES baselines [28] | |||||
| Direct | MobileNet-V3-L [12], no adapt. | 73.32% | 1.4160 | 0.0513 | 1.4673 |
| Modular | HigherHRNet [7] + BPnP [6], no adapt. | 17.27% | 1.3785 | 0.0334 | 1.4119 |
| Independently developed SPARK submissions | |||||
| Modular | HRNet, no adaptation | All | 1.9137 | 0.0412 | 1.9549 |
| Modular | Submitted full system | All | 1.1767 | 0.0285 | 1.2052 |
| Direct | Submitted full system | All | 0.9101 | 0.1335 | 1.0436 |
Fact IDs: f1, f2, f3, f4