# 📐 L2 Spec — Controlled-Source EM (CSEM) — resistivity for hydrocarbons Mismatch-Only Spec
**ID:** `L2-282-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-282`](/artifact/l1/L1-282)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554067
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| Snr db | dB | 0 – 40 |
| N freqs | — | 1 – 30 |
| N stations | — | 5 – 1000 |
| Seawater sigma error | — | 0.0 – 0.1 |
| Source attitude error | — | 0.0 – 0.1 |
| Air wave contamination | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
4.0 + 20.0*seawater_sigma_error + 5.0*air_wave_contamination + 10.0*source_attitude_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`2f4f461cd7cfccbd65edab77192b1345d5ecfbfb340e0a0972ed0a0579667cfa`
## 5. On-chain Registration
- **Chain hash:** `0xdc8662985dcbf8c757968c267762ff70be32cb99726ec0906cdfa7eb2c8403fb`
- **Chain tx hash:** `0xe2d5adad59e3e00d8ae5201a89d86ce8822a30804dc923db897115a8048d0c48`
- **Chain block:** `41554067`
---
## File Mapping
This bundle consists of: `L2-282-001.md`, `L2-282-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-282-001.md` | Source of truth — edit this | Human or LLM |
| `L2-282-001.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 `L2-282-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._