# 📐 L2 Spec — Phase Unwrapping Noisy-Coherence Spec (InSAR family)
**ID:** `L2-390-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-390`](/artifact/l1/L1-390)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.55 · **Delta tier:** 5
> **⛓ On-chain block:** 41555201
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 – 4096 |
| W | px | 128 – 4096 |
| Sigma phi | — | 0.05 – 2.0 |
| Coherence floor | — | 0.1 – 1.0 |
| Undersampling ratio | — | 0.5 – 1.0 |
| Local fringe gradient | — | 0.1 – 3.0 |
| Discontinuity fraction | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
0.05 + sigma_phi / sqrt(coherence_floor) + 2.0 * discontinuity_fraction
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.55 |
| Delta tier | 5 |
## 4. Fingerprint
`72580081955adcbb8ff4f4aa51c8ad5cee474e31119c46fe686f5bd33f96cbd7`
## 5. On-chain Registration
- **Chain hash:** `0xc29e2ed48f2aa87a5f1097cc3e0914bcc40cba7f1c6aeec2a87163f8614f33f8`
- **Chain tx hash:** `0x96c2e7ece53f8982e8e342a4dc96278061edcc38309b43ae418284eeccff171c`
- **Chain block:** `41555201`
---
## File Mapping
This bundle consists of: `L2-390-001.md`, `L2-390-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-390-001.md` | Source of truth — edit this | Human or LLM |
| `L2-390-001.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 `L2-390-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._