> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wherobots.com/llms.txt
> Use this file to discover all available pages before exploring further.

# RS_SRID

Returns the spatial reference system identifier (SRID) of the raster geometry. Returns 0 if the raster has no CRS defined or if the CRS is a custom (non-EPSG) coordinate reference system. To retrieve the full CRS definition for custom CRS, use [RS\_CRS](/reference/wherobots-db/raster-data/operators/RS_CRS).

## Signatures

```sql theme={"system"}
RS_SRID (raster: Raster)
```

## Parameters

<ParamField body="raster" type="Raster" required>
  The input raster.
</ParamField>

## Return type

<ResponseField type="Integer">
  An integer value.
</ResponseField>

## Example

```sql theme={"system"}
SELECT RS_SRID(raster) FROM raster_table
```

```
3857
```