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Expand technical review with literature methodology and full architecture

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docs/OrbitSight_Full_Technical_Proposal_Review.md CHANGED
@@ -93,6 +93,86 @@ recall, F1, and AP/mAP at IoU 0.5. The competition additionally calls for end-to
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  below 40 ms on an Intel Core i9-12900H CPU. There is no track-ID column, so tracking matters
94
  only when it improves the emitted detection stream.
95
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
96
  ## 2. Development history at a glance
97
 
98
  The following table separates comparable leakage-free results from historical development
@@ -406,53 +486,280 @@ checkpoint SHA-256 is:
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  `5f176b9baffc3478b1aaada13277e2c6093ba02439b76b8330cb8d654f5f554d`
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409
- ## 10. Compact student architecture
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
410
 
411
- ### 10.1 Heavy teacher versus compact student
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
412
 
413
  | Component | Heavy V5/V7 branch | CPU student |
414
  |---|---:|---:|
415
  | Input | 3×640×640 | 3×640×640 |
416
  | Backbone widths | 32, 64, 128, 256 | 4, 8, 16, 32 |
417
- | Detection-head width | 128 | 16 |
418
- | Recurrent dilations | 1, 2, 4, 8 | 1, 2, 4, 8 |
419
  | Parameters | 8,588,339 | 135,111 |
420
- | Relative size | 1× | 63.6× smaller |
421
- | Runtime role | Training teacher | Deployed CPU model |
422
 
423
  ![Heavy teacher versus compact student](full_proposal_assets/heavy_vs_student.png)
424
 
425
- The student does not shrink every dimension. It preserves the 640×640 input, stride-4 output,
426
- four recurrent stages, and multi-scale detection pattern. It primarily removes channel width.
427
- That is the correct trade for tiny targets: channel width costs computation, while spatial
428
- resolution protects localization.
429
 
430
- ### 10.2 What happens inside one window
431
 
432
- 1. **Input tensor:** positive count, negative count, and recency arrive as a 640×640 tensor.
433
- 2. **Stage 1:** a narrow convolution extracts edges and local event clusters at high spatial
434
- resolution. A ConvLSTM mixes this evidence with the previous window.
435
- 3. **Stages 2–4:** spatial resolution decreases while channels and context grow. Dilations
436
- allow later stages to see wider neighborhoods without a large kernel.
437
- 4. **Feature pyramid:** features at different scales are passed to the detector so a tiny,
438
- medium, or bright elongated response can be localized at an appropriate level.
439
- 5. **Anchor-free head:** each grid location predicts objectness, center offset, width, and
440
- height. The student is single-class: the question is RSO versus background.
441
- 6. **NMS and top-one ranking:** overlapping proposals are suppressed and the best remaining
442
- proposal is sent to tracking.
443
 
444
- An auxiliary segmentation head helps shape features during training but is skipped at
445
- inference. The quality head and sensor-conditioning branch are disabled. Keeping unused
446
- training-only work out of inference protects the latency budget.
447
 
448
- ### 10.3 Why recurrence remains in such a small network
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
449
 
450
- On low-SNR windows, the RSO may contribute too few events for a reliable single-window
451
- decision. ConvLSTM state acts like a learned short-term memory: it can retain a weak pattern
452
- that appears consistently over consecutive windows. Removing recurrence would save compute,
453
- but it would discard the most direct answer to signal starvation.
454
 
455
- ## 11. Detection to tracking
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
456
 
457
  The detector proposes appearance-based boxes. The tracker imposes short-horizon physical
458
  consistency. Each track maintains:
@@ -478,7 +785,7 @@ This is intentionally simple. More elaborate motion gates were tested, but measu
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  motion was slow enough that consecutive boxes overlap. IoU association was therefore more
479
  reliable than a complex motion-only discriminator.
480
 
481
- ## 12. Distilled student results
482
 
483
  Before the final no-retrain adjustments, the distilled checkpoint produced:
484
 
@@ -503,7 +810,7 @@ The last number is why both percentiles and maxima are reported. The system comf
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  the steady-state p95 objective locally, but scheduling outliers still existed in the longer
504
  profile.
505
 
506
- ## 13. Final no-retrain improvements
507
 
508
  With the checkpoint and architecture frozen, only low-cost constants were screened:
509
 
@@ -534,7 +841,7 @@ policy remained comfortably under the local p95 limit and introduced no expensiv
534
  The gains are modest but consistent across both aggregate views. No weight, layer, or tensor
535
  shape changed.
536
 
537
- ## 14. Current per-sequence behavior
538
 
539
  | Recording | Sensor | F1 | AP | Precision | Recall | Main interpretation |
540
  |---|---|---:|---:|---:|---:|---|
@@ -554,7 +861,7 @@ one is primarily ranking/clutter, and the other is primarily missing evidence.
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555
  ![Representative localization failures](../competition_ready_improved_cpu_student/visualizations/promoted_failure_cases.png)
556
 
557
- ## 15. Docker and reproducibility architecture
558
 
559
  The final Linux/amd64 image is designed to be inspected and run without network access. It
560
  contains:
@@ -587,7 +894,7 @@ Archive validation checks the Linux/amd64 manifest, layer diff IDs, automatic co
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  mount contract, output schema, model hash, runtime dependencies, calibration constants,
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  tracker settings, and baked model-structure text.
589
 
590
- ## 16. Evidence boundaries and scientific honesty
591
 
592
  Three different claims must not be confused:
593
 
@@ -605,7 +912,7 @@ The leakage-free aggregate removes the known DAVIS session overlap, but the rema
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  have still been used for diagnostics. “Leakage-free” here means free of that known training-
606
  session contamination, not untouched by all development decisions.
607
 
608
- ## 17. Why the final student is the recommended submission
609
 
610
  The heavy hybrid has the best local accuracy but fails the CPU requirement by an order of
611
  magnitude. V5 has a cleaner scientific history but its corrected full-tail latency exceeded
@@ -625,7 +932,7 @@ student offers:
625
  This is a practical systems decision rather than a claim that the student is universally
626
  more accurate than every predecessor.
627
 
628
- ## 18. Recommended next work
629
 
630
  If new recordings become available, the next work should be data-centered rather than another
631
  threshold sweep:
@@ -645,7 +952,7 @@ For model research, the highest-value directions are:
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  - measure container startup, file reading, formatting, workbook creation, and disk output on
646
  the organizer's exact i9-12900H hardware.
647
 
648
- ## 19. Conclusion
649
 
650
  OrbitSight progressed from an honest sub-0.1 baseline to a complete real-time CPU system by
651
  treating data contracts, localization, temporal reasoning, deployment, and evaluation as one
@@ -661,14 +968,28 @@ transparent evidence, explicit limitations, and a reproducible offline delivery
661
 
662
  ## Selected references
663
 
664
- 1. Y. Alkendi et al., “Dynamic Space Object Detection with Neuromorphic Vision Sensors,”
 
 
 
 
 
 
665
  European Conference on Space Debris, 2025.
666
- 2. M. Gehrig and D. Scaramuzza, “Recurrent Vision Transformers for Object Detection with
 
667
  Event Cameras,” CVPR, 2023.
668
- 3. Y. Zhang et al., “ByteTrack: Multi-Object Tracking by Associating Every Detection Box,”
669
- ECCV, 2022.
670
- 4. Z. Zheng et al., “Distance-IoU Loss: Faster and Better Learning for Bounding Box
671
- Regression,” AAAI, 2020.
 
 
 
 
 
 
 
672
 
673
  ## Primary local evidence
674
 
 
93
  below 40 ms on an Intel Core i9-12900H CPU. There is no track-ID column, so tracking matters
94
  only when it improves the emitted detection stream.
95
 
96
+ ## Literature review and design lineage
97
+
98
+ OrbitSight is an application-specific synthesis rather than a direct reproduction of one published
99
+ network. Its design draws on neuromorphic sensing, recurrent event detection, anchor-free dense
100
+ detection, model compression, and detection-assisted tracking.
101
+
102
+ ### Event cameras and space situational awareness
103
+
104
+ Gallego et al. formalize the event-camera model: a pixel reports a change in log intensity rather
105
+ than an absolute image sample. The literature emphasizes microsecond timing, high dynamic range,
106
+ low motion blur, and sparse output, while warning that frame algorithms require an event
107
+ representation or event-native computation. OrbitSight preserves polarity and within-window timing,
108
+ but packs events into 40 ms tensors so convolutional and recurrent operations run efficiently on a
109
+ CPU. [Gallego et al., *Event-based Vision: A Survey*, TPAMI 2020](https://doi.org/10.1109/TPAMI.2020.3008413).
110
+
111
+ Afshar et al. demonstrated event-based RSO detection and tracking across sensors and observing sites.
112
+ Ralph et al. subsequently studied astrometric calibration and source characterization for event-based
113
+ space imaging. These works motivate OrbitSight's explicit sensor profiles, native-coordinate
114
+ reconstruction, and treatment of preprocessing and coordinate mapping as part of the model contract.
115
+ [Afshar et al., *Event-based Object Detection and Tracking for Space Situational Awareness*,
116
+ 2019](https://arxiv.org/abs/1911.08730); [Ralph et al., *Astrometric Calibration and Source
117
+ Characterisation of Neuromorphic Event-based Cameras for Space Imaging*,
118
+ 2022](https://arxiv.org/abs/2211.09939).
119
+
120
+ ### Recurrent event-based object detection
121
+
122
+ Perot et al.'s Recurrent Event-camera Detector showed that direct event representations combined with
123
+ recurrent memory outperform feed-forward event detectors because state integrates evidence through
124
+ time. RVT later showed that multi-stage recurrent backbones can obtain a favorable latency/accuracy
125
+ tradeoff. OrbitSight adopts direct event tensors, multi-scale features, and persistent temporal state,
126
+ but uses narrow convolutions and ConvLSTM instead of a transformer for an offline CPU target and tiny
127
+ objects. [Perot et al., *Learning to Detect Objects with a 1 Megapixel Event Camera*, NeurIPS
128
+ 2020](https://proceedings.neurips.cc/paper/2020/hash/c213877427b46fa96cff6c39e837ccee-Abstract.html);
129
+ [Gehrig and Scaramuzza, *Recurrent Vision Transformers for Object Detection With Event Cameras*,
130
+ CVPR 2023](https://openaccess.thecvf.com/content/CVPR2023/html/Gehrig_Recurrent_Vision_Transformers_for_Object_Detection_With_Event_Cameras_CVPR_2023_paper.html).
131
+
132
+ ConvLSTM replaces fully connected state transitions with spatial convolutions, retaining *where* weak
133
+ evidence occurred. OrbitSight places one after every downsampling stage and uses dilations 1, 2, 4,
134
+ and 8 to enlarge spatial context without changing tensor shapes. [Shi et al., *Convolutional LSTM
135
+ Network*, NeurIPS 2015](https://proceedings.neurips.cc/paper/2015/hash/07563a3fe3bbe7e3ba84431ad9d055af-Abstract.html).
136
+
137
+ ### Anchor-free detection, imbalance, and localization
138
+
139
+ FCOS established fully convolutional anchor-free prediction; YOLOX paired anchor-free boxes with a
140
+ decoupled head. OrbitSight adopts those ideas with custom assignment and scoring for one RSO class.
141
+ It predicts raw center offsets and log sizes on three scales without an anchor bank. [Tian et al.,
142
+ *FCOS*, ICCV 2019](https://openaccess.thecvf.com/content_ICCV_2019/html/Tian_FCOS_Fully_Convolutional_One-Stage_Object_Detection_ICCV_2019_paper.html);
143
+ [Ge et al., *YOLOX*, 2021](https://arxiv.org/abs/2107.08430).
144
+
145
+ Dense event tensors create tens of thousands of background cells for at most one target. Focal loss
146
+ suppresses easy negatives so hard examples control learning. OrbitSight uses sigmoid focal BCE for
147
+ objectness. CIoU combines overlap, center distance, and aspect-ratio consistency, aligning training
148
+ more closely with the IoU≥0.5 metric than independent coordinate L1. [Lin et al., *Focal Loss for
149
+ Dense Object Detection*, ICCV 2017](https://openaccess.thecvf.com/content_ICCV_2017/papers/Lin_Focal_Loss_for_ICCV_2017_paper.pdf);
150
+ [Zheng et al., *Distance-IoU Loss*, AAAI 2020](https://ojs.aaai.org/index.php/AAAI/article/view/6999).
151
+
152
+ ### Distillation and tracking
153
+
154
+ Knowledge distillation transfers useful behavior from an expensive model or ensemble into a smaller
155
+ deployable network. OrbitSight follows that deployment logic but does not blindly copy teacher output:
156
+ human boxes remain authoritative, matched teacher boxes provide low-weight targets, and proposals in
157
+ human-empty windows become negative evidence. [Hinton, Vinyals, and Dean, *Distilling the Knowledge
158
+ in a Neural Network*, 2015](https://arxiv.org/abs/1503.02531).
159
+
160
+ ByteTrack showed the value of associating lower-confidence detections. OrbitSight evaluated that
161
+ two-tier idea, but production emits only stable global top-one at 0.10, making the nominal low tier
162
+ unreachable. The final system is therefore a single-tier constant-velocity Kalman/coast tracker using
163
+ the same association machinery. [Zhang et al., *ByteTrack*, ECCV
164
+ 2022](https://www.ecva.net/papers/eccv_2022/papers_ECCV/papers/136820001.pdf).
165
+
166
+ ### OrbitSight's design contribution
167
+
168
+ - a polarity/recency representation with sensor-specific event denoising;
169
+ - a full-resolution but ultra-narrow recurrent detector;
170
+ - single-class objectness decoding without a redundant class multiplier;
171
+ - selective, human-authoritative distillation from a sensor-routed teacher;
172
+ - weights bound to preprocessing and coordinate-mapping fingerprints;
173
+ - exact stable top-one decoding that avoids NMS without changing the selected box;
174
+ - one evaluated detector/tracker/writer deployment contract.
175
+
176
  ## 2. Development history at a glance
177
 
178
  The following table separates comparable leakage-free results from historical development
 
486
 
487
  `5f176b9baffc3478b1aaada13277e2c6093ba02439b76b8330cb8d654f5f554d`
488
 
489
+ ## 10. Final-model methodology
490
+
491
+ This section describes how the final student was produced and evaluated. Section 11 then defines
492
+ the frozen network and inference path component by component.
493
+
494
+ ### 10.1 Research questions and temporal unit
495
+
496
+ Development asked whether one model could localize tiny RSOs across all three sensor families,
497
+ inherit useful sensor-specific behavior from the heavy hybrid, and keep the complete deployed path
498
+ below 40 ms. The atomic example is a half-open 40,000 µs event interval. Window phase is anchored to
499
+ the sequence timestamp contract. Recurrent, BA, and tracker state are initialized at the start of a
500
+ sequence, advanced exactly once per window, and destroyed at the boundary.
501
+
502
+ Training uses ordered segments, not shuffled independent frames. Final distillation used 20 consecutive
503
+ windows per segment—0.8 seconds of temporal context—and batches of 16 independent segments. Each batch
504
+ member carries its own four hidden/cell state pairs before truncated backpropagation detaches them.
505
+
506
+ ### 10.2 Data preparation
507
+
508
+ For every window the method:
509
+
510
+ 1. memory-maps and timestamp-slices events;
511
+ 2. applies the sensor-specific neighborhood/time BA rule;
512
+ 3. builds positive-count, negative-count, and latest-event-recency planes;
513
+ 4. area-resizes the planes to 640×640;
514
+ 5. maps human boxes with the same pixel-center convention;
515
+ 6. builds the optional per-event auxiliary target.
516
 
517
+ Counts remain raw. Stateful BA, sensor FiLM, hot-pixel changes, and target-event thinning are disabled
518
+ in the final route. Cache fingerprints bind the source, sensor profile, 40 ms phase, input size, count
519
+ transform, area resize, and coordinate mapping. This prevents a shape-compatible checkpoint from being
520
+ used with semantically different preprocessing, the failure that invalidated V6.
521
+
522
+ ### 10.3 Human-authoritative teacher evidence
523
+
524
+ The V5/V7 router runs offline. Its pre-tracker proposals are stored in sidecars aligned one-to-one with
525
+ student windows and marked as matched or unmatched against human GT. Post-tracker teacher boxes are
526
+ diagnostic only. The selective objective is:
527
+
528
+ ```text
529
+ L_total = L_human
530
+ + 0.15 L_teacher-objectness-on-matched-GT
531
+ + 0.25 L_teacher-box-on-matched-GT
532
+ + 0.35 L_teacher-empty-window-negative
533
+ ```
534
+
535
+ Teacher scores below 0.05 are ignored. Matched proposals supply a BCE confidence target and Smooth-L1
536
+ encoded-box target. A proposal in a human-empty window pushes the corresponding student objectness
537
+ toward zero. An unmatched teacher proposal never creates a positive label. The teacher is therefore a
538
+ ranking guide and hard-negative miner, not a replacement annotator.
539
+
540
+ ### 10.4 Optimization protocol
541
+
542
+ The final A100 run used 36 epochs, 260 updates per epoch, and 9,360 optimizer steps:
543
+
544
+ | Item | Final setting |
545
+ |---|---:|
546
+ | Optimizer | Adam |
547
+ | Initial / minimum LR | 5×10⁻⁴ / 1×10⁻⁵ |
548
+ | Warm-up / schedule | 100 steps / cosine decay |
549
+ | Precision | FP32; TF32 disabled |
550
+ | Gradient-norm clip | 1.0 |
551
+ | Batch / segment | 16 / 20 windows |
552
+ | Negative/positive target | 2.0 |
553
+ | Maximum oversampling | 4.0× |
554
+ | Human box loss | pixel-inclusive CIoU, weight 2.0 |
555
+ | Auxiliary segmentation | BCE, weight 0.5 |
556
+ | Objectness target floor | 1.0 throughout |
557
+ | Quality head / loss | disabled / 0.0 |
558
+ | Seed | 1337 |
559
+
560
+ Adam state, scheduler, RNG, batching order, partial epoch progress, preprocessing fingerprint, and the
561
+ training contract were included in exact-resume checkpoints. A remote disconnect therefore resumed
562
+ the same stochastic run rather than launching a similar but different experiment.
563
+
564
+ ### 10.5 Evaluation methodology
565
+
566
+ Predictions are scored only after native mapping, calibration, tracking, clipping, top-one selection,
567
+ sensor output gating, and integer writer projection. IoU uses the official pixel-inclusive convention.
568
+ Metrics are reported for the three-sequence leakage-free aggregate and all four local recordings.
569
+ Because every remaining recording has influenced diagnostics, these are reproducibility and local
570
+ comparison results—not blind-generalization proof. Latency is measured after warm-up at streaming
571
+ batch one and reports mean, per-sequence p95, and maximum rather than forward-pass mean alone.
572
+
573
+ ## 11. Final model architecture: complete component reference
574
+
575
+ ### 11.1 Frozen architecture contract
576
+
577
+ | Property | Final value |
578
+ |---|---:|
579
+ | Class | `OrbitSightDetector` |
580
+ | Inference input | 1×3×640×640 |
581
+ | Backbone widths | 4, 8, 16, 32 |
582
+ | ConvLSTM dilations | 1, 2, 4, 8 |
583
+ | Detection scales | stride 4, 8, 16 |
584
+ | Head width | 16 |
585
+ | Classes | one RSO foreground class |
586
+ | Stored parameters | 135,111 |
587
+ | Quality head / sensor FiLM | absent / absent |
588
+ | Auxiliary segmentation | stored; training-only execution |
589
+ | Classification towers | stored for compatibility; never executed |
590
+
591
+ ![Exact final student architecture](full_proposal_assets/final_student_architecture.png)
592
+
593
+ ### 11.2 Compression decision
594
 
595
  | Component | Heavy V5/V7 branch | CPU student |
596
  |---|---:|---:|
597
  | Input | 3×640×640 | 3×640×640 |
598
  | Backbone widths | 32, 64, 128, 256 | 4, 8, 16, 32 |
599
+ | Head width | 128 | 16 |
600
+ | Dilations | 1, 2, 4, 8 | 1, 2, 4, 8 |
601
  | Parameters | 8,588,339 | 135,111 |
602
+ | Runtime role | Offline teacher | Deployed model |
 
603
 
604
  ![Heavy teacher versus compact student](full_proposal_assets/heavy_vs_student.png)
605
 
606
+ The 63.6× reduction comes mainly from channel width. Input resolution, recurrence, the finest stride-4
607
+ grid, and three detection scales remain because spatial quantization is expensive for 6–11 pixel targets.
 
 
608
 
609
+ ### 11.3 Input representation
610
 
611
+ `X ∈ R^(B×3×640×640)` is float32. Channel 0 counts positive-polarity events; channel 1 counts negative
612
+ events; channel 2 records normalized recency of the latest event. Empty pixels are zero. This preserves
613
+ brightness-change sign and within-window order without reconstructing an intensity image.
 
 
 
 
 
 
 
 
614
 
615
+ ### 11.4 Stem
 
 
616
 
617
+ ```text
618
+ (B,3,640,640)
619
+ → Conv2d(3→4, kernel 3, stride 1, pad 1)
620
+ → BatchNorm2d(4) → SiLU
621
+ = (B,4,640,640)
622
+ ```
623
+
624
+ The stem has 120 parameters. SiLU is `x·sigmoid(x)`. There is no pooling or tokenization.
625
+
626
+ ### 11.5 Four downsampling and recurrent stages
627
+
628
+ Each stage performs 3×3 stride-2 convolution, BatchNorm, SiLU, then ConvLSTM. There are no residual
629
+ blocks, attention layers, transformer tokens, or active sensor-conditioning layers.
630
+
631
+ | Stage | Down mapping | Feature and state | Dilation | Down params | ConvLSTM params | Head input? |
632
+ |---|---|---|---:|---:|---:|---|
633
+ | 1 | 4→4 | B×4×320×320 | 1 | 156 | 1,168 | No |
634
+ | 2 | 4→8 | B×8×160×160 | 2 | 312 | 4,640 | Yes, stride 4 |
635
+ | 3 | 8→16 | B×16×80×80 | 4 | 1,200 | 18,496 | Yes, stride 8 |
636
+ | 4 | 16→32 | B×32×40×40 | 8 | 4,704 | 73,856 | Yes, stride 16 |
637
+
638
+ Stage 1 still matters: its high-resolution recurrent output feeds all later stages. The last three
639
+ tensors are independent multi-scale features. Unlike a classical FPN, there is **no top-down pathway,
640
+ lateral addition, or cross-scale fusion**.
641
+
642
+ ### 11.6 Every ConvLSTM operation
643
 
644
+ At time `t`, current feature `X_t` and previous hidden state `H_(t−1)` are concatenated. One dilated
645
+ 3×3 convolution emits four channel groups:
 
 
646
 
647
+ ```text
648
+ [I,F,O,G] = Conv3×3_dilated([X_t,H_(t−1)])
649
+ i=sigmoid(I), f=sigmoid(F), o=sigmoid(O), g=tanh(G)
650
+ C_t = f ⊙ C_(t−1) + i ⊙ g
651
+ H_t = o ⊙ tanh(C_t)
652
+ ```
653
+
654
+ The input, forget, and output gates govern writing, retaining, and exposing memory. Both `H_t` and
655
+ `C_t` persist. At inference the four pairs have shapes 1×4×320×320, 1×8×160×160,
656
+ 1×16×80×80, and 1×32×40×40. Dilation gives effective 3×3, 5×5, 9×9, and 17×17 footprints without
657
+ adding weights. State begins at zero and resets only at sequence boundaries.
658
+
659
+ ### 11.7 Three active detection heads
660
+
661
+ For each returned feature, the active regression/objectness tower is:
662
+
663
+ ```text
664
+ feature C×H×W
665
+ → Conv2d(C→16,3×3,pad1) → SiLU
666
+ → Conv2d(16→16,3×3,pad1) → SiLU
667
+ ├→ Conv2d(16→4,1×1): raw box vector
668
+ └→ Conv2d(16→1,1×1): objectness logit
669
+ ```
670
+
671
+ | Scale | Feature | Tower + box + objectness params | Outputs |
672
+ |---|---:|---:|---|
673
+ | stride 4 | 8×160×160 | 3,488 + 68 + 17 | 4×160×160 and 1×160×160 |
674
+ | stride 8 | 16×80×80 | 4,640 + 68 + 17 | 4×80×80 and 1×80×80 |
675
+ | stride 16 | 32×40×40 | 6,944 + 68 + 17 | 4×40×40 and 1×40×40 |
676
+
677
+ There are 25,600 + 6,400 + 1,600 = **33,600 candidate cells**. Four regression channels encode raw
678
+ x/y offsets and log width/height. Objectness alone asks whether an RSO occupies the cell.
679
+
680
+ ### 11.8 Compatibility classification modules
681
+
682
+ Three classification towers and 1×1 predictors remain in the checkpoint so historical state-dictionary
683
+ keys load strictly. They contain 15,123 parameters, but `compute_cls=False`: their convolutions are not
684
+ executed, their logits are not trained by the final loss, and the decoder never reads them. In a
685
+ single-class problem, multiplying objectness by a redundant class probability would square/compress
686
+ confidence without adding information. Final score is `sigmoid(objectness)`. No quality head exists.
687
+
688
+ ### 11.9 Auxiliary segmentation head
689
+
690
+ A nine-parameter 1×1 convolution maps the eight-channel stride-4 feature to one 160×160 logit plane.
691
+ Per-event labels supervise it with BCE at weight 0.5, helping the finest features retain target-local
692
+ structure. It runs only while `model.training` is true; deployment skips it entirely.
693
+
694
+ ### 11.10 Target assignment and hard loss
695
+
696
+ A human box is assigned to the scale whose `4×stride` nominal size is closest to its maximum dimension.
697
+ The rounded center and radius-1 neighborhood—up to 3×3 cells—are positive. At cell `(g_x,g_y)`:
698
+
699
+ ```text
700
+ t_x=c_x/s−g_x, t_y=c_y/s−g_y,
701
+ t_w=w/s, t_h=h/s
702
+ ```
703
+
704
+ Objectness uses focal BCE with alpha 0.25 and gamma 2.0, normalized by positive assigned cells and
705
+ clamped to one on empty windows. The positive objectness floor was 1.0 during final distillation.
706
+ Regression uses pixel-inclusive CIoU: `1−IoU`, normalized center distance, and aspect-ratio penalty.
707
+ It therefore supplies gradient even before two tiny boxes overlap. Auxiliary BCE and the selective KD
708
+ terms described in Section 10 complete the objective.
709
+
710
+ ### 11.11 Anchor-free decode
711
+
712
+ For raw `(r_x,r_y,r_w,r_h)` at grid cell `(g_x,g_y)` and stride `s`:
713
+
714
+ ```text
715
+ c_x=(g_x+r_x)s c_y=(g_y+r_y)s
716
+ w=exp(clamp(r_w,6))s h=exp(clamp(r_h,6))s
717
+ score=sigmoid(objectness)
718
+ ```
719
+
720
+ Offsets are intentionally raw, matching training. Exponentiation guarantees positive sizes and the
721
+ upper clamp prevents overflow.
722
+
723
+ ### 11.12 Exact stable top-one decode
724
+
725
+ Production requests one proposal. The decoder concatenates three score maps in fixed scale/grid order,
726
+ masks values below 0.10, and applies `argmax`. Exact ties select the first index deterministically. Only
727
+ the winning cell's box is decoded.
728
+
729
+ This exactly matches the first result of score-ordered NMS: the global maximum is selected before any
730
+ overlap comparison can suppress it. Thus production avoids materializing/sorting 33,600 boxes and the
731
+ Python NMS loop without approximating or changing the selected prediction. Generic pixel-inclusive NMS
732
+ and its 1,000-candidate pre-bound remain only for multi-detection diagnostics.
733
+
734
+ ### 11.13 Native-coordinate reconstruction
735
+
736
+ The winning box is inverted through recorded area-resize geometry with pixel-center rounding. DVX
737
+ width/height receives the frozen 0.98 calibration before association. Geometry is clipped in native
738
+ sensor coordinates, but remains floating point until the writer performs final legal integer projection.
739
+
740
+ ### 11.14 Complete parameter inventory
741
+
742
+ | Module group | Parameters | Deployment execution |
743
+ |---|---:|---|
744
+ | Stem | 120 | Yes |
745
+ | Four downsampling blocks | 6,372 | Yes |
746
+ | Four ConvLSTM cells | 98,160 | Yes |
747
+ | Three regression towers | 15,072 | Yes |
748
+ | Box predictors | 204 | Yes |
749
+ | Objectness predictors | 51 | Yes |
750
+ | Compatibility classification modules | 15,123 | No |
751
+ | Auxiliary segmentation | 9 | No |
752
+ | **Total** | **135,111** | — |
753
+
754
+ ### 11.15 End-to-end state machine
755
+
756
+ For each sequence: identify sensor and reset state; slice 40 ms; denoise; form the 3×640×640 tensor;
757
+ run stem and four ConvLSTMs; run three active heads; choose/decode global top-one; map/calibrate native
758
+ geometry; update Kalman/coast state; retain at most one box; apply the sensor gate; project integer
759
+ fields; write the row; and reset everything before another sequence. Docker latency covers this path,
760
+ not merely the neural forward call.
761
+
762
+ ## 12. Detection to tracking
763
 
764
  The detector proposes appearance-based boxes. The tracker imposes short-horizon physical
765
  consistency. Each track maintains:
 
785
  motion was slow enough that consecutive boxes overlap. IoU association was therefore more
786
  reliable than a complex motion-only discriminator.
787
 
788
+ ## 13. Distilled student results
789
 
790
  Before the final no-retrain adjustments, the distilled checkpoint produced:
791
 
 
810
  the steady-state p95 objective locally, but scheduling outliers still existed in the longer
811
  profile.
812
 
813
+ ## 14. Final no-retrain improvements
814
 
815
  With the checkpoint and architecture frozen, only low-cost constants were screened:
816
 
 
841
  The gains are modest but consistent across both aggregate views. No weight, layer, or tensor
842
  shape changed.
843
 
844
+ ## 15. Current per-sequence behavior
845
 
846
  | Recording | Sensor | F1 | AP | Precision | Recall | Main interpretation |
847
  |---|---|---:|---:|---:|---:|---|
 
861
 
862
  ![Representative localization failures](../competition_ready_improved_cpu_student/visualizations/promoted_failure_cases.png)
863
 
864
+ ## 16. Docker and reproducibility architecture
865
 
866
  The final Linux/amd64 image is designed to be inspected and run without network access. It
867
  contains:
 
894
  mount contract, output schema, model hash, runtime dependencies, calibration constants,
895
  tracker settings, and baked model-structure text.
896
 
897
+ ## 17. Evidence boundaries and scientific honesty
898
 
899
  Three different claims must not be confused:
900
 
 
912
  have still been used for diagnostics. “Leakage-free” here means free of that known training-
913
  session contamination, not untouched by all development decisions.
914
 
915
+ ## 18. Why the final student is the recommended submission
916
 
917
  The heavy hybrid has the best local accuracy but fails the CPU requirement by an order of
918
  magnitude. V5 has a cleaner scientific history but its corrected full-tail latency exceeded
 
932
  This is a practical systems decision rather than a claim that the student is universally
933
  more accurate than every predecessor.
934
 
935
+ ## 19. Recommended next work
936
 
937
  If new recordings become available, the next work should be data-centered rather than another
938
  threshold sweep:
 
952
  - measure container startup, file reading, formatting, workbook creation, and disk output on
953
  the organizer's exact i9-12900H hardware.
954
 
955
+ ## 20. Conclusion
956
 
957
  OrbitSight progressed from an honest sub-0.1 baseline to a complete real-time CPU system by
958
  treating data contracts, localization, temporal reasoning, deployment, and evaluation as one
 
968
 
969
  ## Selected references
970
 
971
+ 1. G. Gallego et al., “Event-based Vision: A Survey,” IEEE TPAMI, 2020.
972
+ DOI: 10.1109/TPAMI.2020.3008413.
973
+ 2. S. Afshar et al., “Event-based Object Detection and Tracking for Space Situational
974
+ Awareness,” arXiv:1911.08730, 2019.
975
+ 3. N. O. Ralph et al., “Astrometric Calibration and Source Characterisation of the Latest
976
+ Generation Neuromorphic Event-based Cameras for Space Imaging,” arXiv:2211.09939, 2022.
977
+ 4. Y. Alkendi et al., “Dynamic Space Object Detection with Neuromorphic Vision Sensors,”
978
  European Conference on Space Debris, 2025.
979
+ 5. E. Perot et al., “Learning to Detect Objects with a 1 Megapixel Event Camera,” NeurIPS, 2020.
980
+ 6. M. Gehrig and D. Scaramuzza, “Recurrent Vision Transformers for Object Detection with
981
  Event Cameras,” CVPR, 2023.
982
+ 7. X. Shi et al., “Convolutional LSTM Network: A Machine Learning Approach for Precipitation
983
+ Nowcasting,” NeurIPS, 2015.
984
+ 8. Z. Tian et al., “FCOS: Fully Convolutional One-Stage Object Detection,” ICCV, 2019.
985
+ 9. Z. Ge et al., “YOLOX: Exceeding YOLO Series in 2021,” arXiv:2107.08430, 2021.
986
+ 10. T.-Y. Lin et al., “Focal Loss for Dense Object Detection,” ICCV, 2017.
987
+ 11. Z. Zheng et al., “Distance-IoU Loss: Faster and Better Learning for Bounding Box
988
+ Regression,” AAAI, 2020. DOI: 10.1609/aaai.v34i07.6999.
989
+ 12. G. Hinton, O. Vinyals, and J. Dean, “Distilling the Knowledge in a Neural Network,”
990
+ arXiv:1503.02531, 2015.
991
+ 13. Y. Zhang et al., “ByteTrack: Multi-Object Tracking by Associating Every Detection Box,”
992
+ ECCV, 2022.
993
 
994
  ## Primary local evidence
995