# Add Poisson Uncertainties

## Summary
Add Poisson uncertainties to the data

## Metadata
- **Module ID:** PoissonUncertainties
- **Module path:** /home/runner/work/MoDaCor/MoDaCor/src/modacor/modules/base_modules/poisson_uncertainties.py
- **Module version:** 20250522.1
- **Keywords:** uncertainties, Poisson

## Required data keys
- signal

## Modifies
- **variances**: Poisson

## Required arguments
- with_processing_keys

## Default configuration
```json
{
  "with_processing_keys": null
}
```

## Argument specification
| Argument | Type | Required | Default | Description |
|---|---|---|---|---|
| `with_processing_keys` | list | Yes | - | ProcessingData keys to update with Poisson variances. |

## References
DOI 10.1088/0953-8984/25/38/383201

## Notes
This is a simple Poisson uncertainty calculation based on the signal intensity