# ⚛  L1 Principle — Shearography (ESPI-based strain imaging)

**ID:** `L1-119` · **Status:** ⊙ Testnet (genesis catalog)

> **🌐 Domain:** Industrial Inspection — *Laser-speckle shearography for defect detection via strain*
> **🎯 Problem class:** linear inverse · **🧮 Solution space:** 2D strain gradient
> **📡 Carrier:** photon · **🌫 Noise:** gaussian
> **⚖ Difficulty (δ):** 5 · **⛓ Block:** 41554212

---

## 🧠 1. Introduction

**Shearography (ESPI-based strain imaging)** is a **linear inverse problem** whose unknown lives in **2D strain gradient** space, within the **Laser-speckle shearography for defect detection via strain** sub-domain of **Industrial Inspection**.

Measurements consist of photons collected by an optical detector via a **shearography espi** sensing mechanism.

The forward operator applies, in order: L · laser illumination operator; L · shear interferometer operator; L · speckle correlation operator; pixel-level spatial averaging on the detector.

Observations are corrupted by additive Gaussian noise. Existence of the recovered 2D strain gradient is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is moderately conditioned (kappa_eff ~= 14); vibration_isolation dominates the stability cliff; speckle_decorrelation and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.

## ⚙ 2. Forward Model

Physical chain: **x** → L · laser illumination → L · shear interferometer → L · speckle correlation → Spatial integration → **y** (detector).

```
y = ∫_A dA `L.speckle_correlation` `L.shear_interferometer` `L.laser_illumination` x + n,    n ~ 𝒩(0, σ²)
```

**Measurement DAG:**

| Primitive | What it does |
|---|---|
| `L.laser_illumination` | L · laser illumination operator |
| `L.shear_interferometer` | L · shear interferometer operator |
| `L.speckle_correlation` | L · speckle correlation operator |
| `int.spatial` | Pixel-level spatial averaging on the detector |

## 🔬 3. Physics Fingerprint

| Property | Value |
|---|---|
| Domain | Industrial Inspection |
| Sub domain | Laser-speckle shearography for defect detection via strain |
| Carrier | photon |
| Problem class | linear_inverse |
| Solution space | 2D_strain_gradient |
| Noise model | gaussian |
| Integration axis | spatial |
| Difficulty delta | 5 |
| L dag | 3.5 |

## 📡 4. Measurement Model

Existence of the recovered 2D strain gradient is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is moderately conditioned (kappa_eff ~= 14); vibration_isolation dominates the stability cliff; speckle_decorrelation and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.

| Metric | Value |
|---|---|
| Metric | PSNR_dB |
| Secondary | SSIM |

## 📏 5. Operating Range (Ω)

**Center problem class:** `shearography` · **Forward operator:** `shearography_forward`

**Center point:**

| Parameter | Unit | Value |
|---|---|---|
| H | px | 1024 |
| W | px | 1024 |
| Snr db | dB | 20 |
| Pixel um | µm | 10 |
| Shear mm | mm | 1 |
| Vibration isolation | — | 1 |
| Speckle decorrelation | — | 0 |
| Illumination uniformity | — | 1 |

**Allowed bounds:**

| Parameter | Unit | Range |
|---|---|---|
| H | px | 256 – 4096 |
| W | px | 256 – 4096 |
| Snr db | dB | 0.0 – 30.0 |
| Pixel um | µm | 1 – 100 |
| Shear mm | mm | 0.1 – 10 |
| Shear calibration | — | 0.0 – 0.1 |
| Vibration isolation | — | 0.3 – 1.0 |
| Speckle decorrelation | — | 0.0 – 0.5 |
| Illumination uniformity | — | 0.5 – 1.0 |

## 🎯 6. Tolerance (ε)

**Center tolerance:** 22.0

| Metric | Range |
|---|---|
| Psnr db | 5.0 – 40.0 |

## ⚖ 7. Hardness Function

Hardness scales as **`epsilon_fn`** on **PSNR_dB**, with κ = `280` and δ = `5`.

## 💾 8. Reference Dataset

- **primary** · weight 1.0 · IPFS _(not pinned yet)_

## 9. On-chain Registration

- **Chain hash:** `0x02a8ae5695a7752450f6e3b65bc6ed6325450fe1f4bc09df8cd8a043ed96a524`
- **Chain tx hash:** `0xfa025a20c50cf1ceae67ffb65e4c31d7a59c486476dd6dea5d4e6aa92125d698`
- **Chain block:** `41554212`

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## File Mapping

This bundle consists of: `L1-119.md`, `L1-119.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L1-119.md` | Source of truth — edit this | Human or LLM |
| `L1-119.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 `L1-119`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._