# 📐 L2 Spec — Ghost Imaging (correlated-photon imaging) Mismatch-Only Spec
**ID:** `L2-153-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-153`](/artifact/l1/L1-153)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.55 · **Delta tier:** 5
> **⛓ On-chain block:** 41554244
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 32 |
| W | px | 32 |
| N pairs | — | 1000 – 100000000 |
| Bucket snr db | dB | 0.0 – 30.0 |
| Photon pair rate | — | 0.1 – 10.0 |
| Reference calibration | — | 0.3 – 1.0 |
| Accidental coincidences | — | 0.0 – 0.5 |
| Environmental decoherence | — | 0.0 – 0.5 |
## 2. Tolerance (ε)
**Type:** `fn`
```
8.0 + 2.5 * log10(N_pairs / 1000) - 10.0 * accidental_coincidences + 6.0 * reference_calibration - 6.0 * environmental_decoherence
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.55 |
| Delta tier | 5 |
## 4. Fingerprint
`d1e5ce5799835bca6b81312efc4eaa2c10f2f15b1d808ce6c0a2b85981e43713`
## 5. On-chain Registration
- **Chain hash:** `0xf41bb4e9cef7dfbeb46981215b0eb32531fd322e627c108379e0ccd11522ceed`
- **Chain tx hash:** `0x86c8928a47b0881509e6b6b5723f2b4b4dfbb2ddb8cd94c1948de1c4f4e401d1`
- **Chain block:** `41554244`
---
## File Mapping
This bundle consists of: `L2-153-001.md`, `L2-153-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-153-001.md` | Source of truth — edit this | Human or LLM |
| `L2-153-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-153-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._