Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# ST\$1DistanceSphere
<a name="ST_DistanceSphere-function"></a>

ST\$1DistanceSphere returns the distance between two point geometries lying on a sphere. 

## Syntax
<a name="ST_DistanceSphere-function-syntax"></a>

```
ST_DistanceSphere(geom1, geom2)
```

```
ST_DistanceSphere(geom1, geom2, radius)
```

## Arguments
<a name="ST_DistanceSphere-function-arguments"></a>

 *geom1*   
A point value in degrees of data type `GEOMETRY` lying on a sphere. The first coordinate of the point is the longitude value. The second coordinate of the point is the latitude value. For 3DZ, 3DM, or 4D geometries, only the first two coordinates are used.

 *geom2*   
A point value in degrees of data type `GEOMETRY` lying on a sphere. The first coordinate of the point is the longitude value. The second coordinate of the point is the latitude value. For 3DZ, 3DM, or 4D geometries, only the first two coordinates are used.

 *radius*   
The radius of a sphere of data type `DOUBLE PRECISION`. If no *radius* is provided, the sphere defaults to Earth and the radius is computed from the World Geodetic System (WGS) 84 representation of the ellipsoid. 

## Return type
<a name="ST_DistanceSphere-function-return"></a>

`DOUBLE PRECISION` in the same units as the radius. If no radius is provided, the distance is in meters.

If *geom1* or *geom2* is null or empty, then null is returned. 

If no *radius* is provided, then the result is in meters along the Earth's surface. 

If *radius* is a negative number, then an error is returned. 

If *geom1* and *geom2* don't have the same value for the spatial reference system identifier (SRID), then an error is returned. 

If *geom1* or *geom2* is not a point, then an error is returned. 

## Examples
<a name="ST_DistanceSphere-function-examples"></a>

The following example SQL computes the distance in kilometers between two points on Earth. 

```
SELECT ROUND(ST_DistanceSphere(ST_Point(-122, 47), ST_Point(-122.1, 47.1))/ 1000, 0);
```

```
  round
-----------
 13
```

The following example SQL computes the distances in kilometers between three airport locations in Germany: Berlin Tegel (TXL), Munich International (MUC), and Frankfurt International (FRA). 

```
WITH airports_raw(code,lon,lat) AS (
(SELECT 'MUC', 11.786111, 48.353889) UNION
(SELECT 'FRA', 8.570556, 50.033333) UNION
(SELECT 'TXL', 13.287778, 52.559722)),
airports1(code,location) AS (SELECT code, ST_Point(lon, lat) FROM airports_raw),
airports2(code,location) AS (SELECT * from airports1)
SELECT (airports1.code || ' <-> ' || airports2.code) AS airports,
round(ST_DistanceSphere(airports1.location, airports2.location) / 1000, 0) AS distance_in_km
FROM airports1, airports2 WHERE airports1.code < airports2.code ORDER BY 1;
```

```
  airports   | distance_in_km 
-------------+----------------
 FRA <-> MUC |            299
 FRA <-> TXL |            432
 MUC <-> TXL |            480
```