# 13 — Sparse SfM

## Status

```text
SPARSE_SFM_V1=IMPLEMENTED
GATE_A=DECISION/HISTORICAL
GATE_B=PASS/FROZEN
GATE_C=PASS/FROZEN
GATE_D=PASS/FROZEN
GATE_E=PASS/FROZEN
GATE_F=PASS/FROZEN
GATE_G=PASS/FROZEN
```

## Authority

`docs/architecture/sparse_sfm.md` is the detailed authority.

## FROZEN

Sparse SfM consumes one exact immutable Track Set and one exact compatible known-calibration scope.

It does not recover unknown intrinsics, infer metric scale, mutate Tracks, or merge unrelated campaigns.

The production Task remains:

```text
sparse_sfm.run/1
```

Its FROZEN CPU1/BATCH1 execution is a specific validated Sparse v1 choice and must not be generalized to unrelated stages.

## CURRENT

```text
REAL_S21_SPARSE_SFM=NOT_EXECUTED
REAL_A6000_SPARSE_SFM=NOT_EXECUTED
REAL_SPARSE_SFM_BLOCKER=KNOWN_CALIBRATION_DATA
```

## PLANNED

Run a dedicated physically calibrated real campaign, reach `READY`, then execute the existing Sparse SfM path as a retained real proof. Do not use historical uncalibrated campaigns to bypass the calibration contract.

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