# SubStation

> SubStation is free, open-source (GPLv3), self-hosted software for astrophotographers. It watches the capture folder, calibrates and grades each sub as it lands (accept, down-weight or reject, with a plain-English reason), and stacks finished datasets into masters. It runs as one Docker container; there is no account and no cloud.

SubStation is a sibling of SQMeter (https://sqmeter.dev). Originals are never deleted or moved, and every grade can be reversed.

## How it works
1. **Watch.** New FITS and XISF files are picked up seconds after they land. NINA, Ekos, ASIAIR and SharpCap folder layouts are recognised.
2. **Calibrate.** Each light is matched to the closest darks, flats and bias by exposure, gain, temperature and filter.
3. **Grade.** FWHM, eccentricity, star count and background are measured and compared with that night’s median.
4. **Stack.** Accepted subs are integrated with quality weights. Masters are marked stale when their inputs change.

## Principles
- **Your originals stay put.** SubStation never deletes or moves a sub. Rejected files stay on disk, and every grade can be reversed.
- **Runs on your hardware.** One Docker container on a NAS, a mini PC or the observatory machine. No account, no cloud.
- **Free and open source.** GPLv3. Read the grading code, change the thresholds, or send a pull request.
- **Readable for everyone.** Every verdict has a shape as well as a colour. WCAG AA contrast and full keyboard control.

## Install
### Docker Compose
Then run docker compose up -d and open port 8480.

```
services:
  substation:
    image: ghcr.io/substation/substation:0.4
    ports:
      - "8480:8480"
    volumes:
      - /volume1/astro:/data
    restart: unless-stopped
```

### Unraid
Available in Community Applications.

```
1  Apps → search "SubStation" → Install
2  Data:        /mnt/user/astro
3  Web UI port: 8480
4  Apply, then open http://tower:8480
```

### Synology
DSM 7.2 or later with Container Manager.

```
1  Package Center → install Container Manager
2  Project → Create → docker-compose.yml
3  Paste the Compose file, set /volume1/astro:/data
4  Build, then open http://nas:8480
```

## Links
- [Documentation](https://substation.dev/docs/): manual, getting started and reference
- [First night guide](https://substation.dev/docs/getting-started/first-night/)
- [Release notes](https://substation.dev/docs/release-notes/)
- [Source code](https://github.com/substation/substation): GPLv3