ST_ANGLE_SPHERE

Description

Calculates the central angle (in degrees) between two points on the Earth's surface. The input parameters are, in order, the longitude of point X, latitude of point X, longitude of point Y, and latitude of point Y.

The central angle refers to the angle at the center of the Earth subtended by the arc connecting the two points.

Sytax

ST_ANGLE_SPHERE( <x_lng>, <x_lat>, <y_lng>, <y_lat>)

参数

parameters	description
<x_lng>	Longitude of point X, of type DOUBLE, with a valid range of [-180, 180]
<y_lng>	Longitude of point Y, of type DOUBLE, with a valid range of [-180, 180]
<x_lat>	Latitude of point X, of type DOUBLE, with a valid range of [-90, 90]
<y_lat>	Latitude of point Y, of type DOUBLE, with a valid range of [-90, 90]

Retuen Value

Returns the central angle between the two points in degrees, of type DOUBLE, with a range of [0, 180].

Edge cases for ST_ANGLE_SPHERE:

• If any input parameter is NULL, returns NULL.
• If any coordinate is out of range (e.g., longitude > 180, latitude < -90), returns NULL.
• If the two points are identical (same longitude and latitude), returns 0.
• If the two points are antipodal (diametrically opposite on the Earth), returns 180.

Example

Calculation of central angle between two adjacent points

select ST_Angle_Sphere(116.35620117, 39.939093, 116.4274406433, 39.9020987219);

+---------------------------------------------------------------------------+
| st_angle_sphere(116.35620117, 39.939093, 116.4274406433, 39.9020987219) |
+---------------------------------------------------------------------------+
|                                                        0.0659823452409903 |
+---------------------------------------------------------------------------+

Two points on the equator with a 45° longitude difference

select ST_Angle_Sphere(0, 0, 45, 0);

+----------------------------------------+
| st_angle_sphere(0.0, 0.0, 45.0, 0.0) |
+----------------------------------------+
|                                     45 |
+----------------------------------------+

Two points with identical coordinates

mysql> SELECT ST_ANGLE_SPHERE(30, 60, 30, 60);
+---------------------------------+
| ST_ANGLE_SPHERE(30, 60, 30, 60) |
+---------------------------------+
|                               0 |
+---------------------------------+

Antipodal points (diametrically opposite)

mysql> SELECT ST_ANGLE_SPHERE(0, 0, 180, 0);
+-------------------------------+
| ST_ANGLE_SPHERE(0, 0, 180, 0) |
+-------------------------------+
|                           180 |
+-------------------------------+

Two points across east-west longitudes (e.g., 170°E and -170°W)

mysql> SELECT ST_ANGLE_SPHERE(170, 30, -170, 30);
+------------------------------------+
| ST_ANGLE_SPHERE(170, 30, -170, 30) |
+------------------------------------+
|                 17.298330210575152 |
+------------------------------------+

Two points across the equator (north and south latitudes)

mysql> SELECT ST_ANGLE_SPHERE(0, 45, 0, -45);
+--------------------------------+
| ST_ANGLE_SPHERE(0, 45, 0, -45) |
+--------------------------------+
|              89.99999999999999 |
+--------------------------------+

Invalid longitude (out of range)

mysql> SELECT ST_ANGLE_SPHERE(190, 30, 10, 30);
+----------------------------------+
| ST_ANGLE_SPHERE(190, 30, 10, 30) |
+----------------------------------+
|                             NULL |
+----------------------------------+

Any parameter is NULL

mysql> SELECT ST_ANGLE_SPHERE(NULL, 30, 10, 30);
+-----------------------------------+
| ST_ANGLE_SPHERE(NULL, 30, 10, 30) |
+-----------------------------------+
|                              NULL |
+-----------------------------------+

Latitude out of range (e.g., 91°N)

mysql> SELECT ST_ANGLE_SPHERE(0, 0, 180, 91);
+--------------------------------+
| ST_ANGLE_SPHERE(0, 0, 180, 91) |
+--------------------------------+
|                           NULL |
+--------------------------------+