# SDSS DR17 spPlate mirror

Byte-for-byte copies of six `spPlate` frames from the Sloan Digital Sky Survey
Data Release 17, mirrored here so that virtual-reference (Icechunk) stores can
resolve chunk reads against object storage. Nothing is reshaped, resampled, or
reshared into a sample format — these are the original FITS files.

## Source

```
https://data.sdss.org/sas/dr17/sdss/spectro/redux/26/<plate>/spPlate-<plate>-<mjd>.fits
```

mirrored to the identical relative path under:

```
gs://insitubatch-bench-insitubatch/astronomy/sdss/dr17/
```

## Why mirror

`data.sdss.org` rate-limits new TCP connections. The multi-plate reference store
is one fiber per chunk (3840 chunks over these six plates), so streaming it needs
thousands of ranged GETs — a load pattern object storage handles trivially and a
university web server does not. Mirroring the bytes keeps the reference store
honest (still pointers, still no reshard) while making it actually streamable.

## License and credit

All SDSS data released in SDSS public data releases are in the public domain:

> "All SDSS data released in our public data releases are considered in the
> public domain."
> — <https://www.sdss.org/collaboration/image-use-policy/>

(SDSS *images* are separately licensed CC-BY and must retain their credits; the
files here are data, not images.)

Work that uses these data should cite SDSS as described at
<https://www.sdss4.org/collaboration/citing-sdss/> — the survey description
paper, the relevant instrumentation papers, and the DR17 data release paper.

Funding acknowledgment and full citation guidance:
<https://www.sdss4.org/collaboration/citing-sdss/>

This mirror is not affiliated with or endorsed by the SDSS collaboration.