# 📐  L2 Spec — Outdoor Noise Propagation — atmospheric refraction + ground effect Mismatch-Only Spec

**ID:** `L2-271-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-271`](/artifact/l1/L1-271)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554053

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| Snr db | dB | -10 – 40 |
| Freq hz | Hz | 20 – 10000 |
| R max m | m | 50 – 20000 |
| N stations | — | 4 – 128 |
| Terrain error | — | 0.0 – 0.3 |
| Temp profile error | — | 0.0 – 0.3 |
| Wind profile error | — | 0.0 – 0.5 |
| Ground impedance error | — | 0.0 – 0.5 |

## 2. Tolerance (ε)

**Type:** `fn`

```
2.0 + 10.0*wind_profile_error + 8.0*temp_profile_error + 6.0*ground_impedance_error
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |

## 4. Fingerprint

`0f55082adedeb60607ef0b077949802cc8e9ca30569e6415c333626120090449`

## 5. On-chain Registration

- **Chain hash:** `0xae512d72002d365a3d6577dd224bb2530e139905f16e82daf2bc305113b39365`
- **Chain tx hash:** `0x81db3c984e8206ab2a3096af948850163b47fb0b9d5e562f0b47a3a36bd7885d`
- **Chain block:** `41554053`

---

## File Mapping

This bundle consists of: `L2-271-001.md`, `L2-271-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-271-001.md` | Source of truth — edit this | Human or LLM |
| `L2-271-001.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 `L2-271-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._