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ST_AZIMUTH

Description​

Enter two points and return the azimuth of the line segment formed by points 1 and 2. Azimuth is the arc of the Angle between the true north line of point 1 and the line segment formed by points 1 and 2.

Syntax​

ST_Azimuth( <point1>, <point2>)

Parameters​

ParametersInstructions
<point1>The first point used to calculate the azimuth
<point2>The second point used to calculate the azimuth

Return Value​

Positive angles are measured clockwise on the sphere. For example, the azimuth of a line segment:

  • North is 0
  • East is PI/2
  • The guide is PI
  • The west is 3PI/2

ST_Azimuth has the following edge cases:

  • Return NULL if both input points are the same.
  • NULL is returned if the two input points are perfect mapping points.
  • An error is thrown if any of the input geographies are not a single point or are empty geographies

Examples​

SELECT st_azimuth(ST_Point(1, 0),ST_Point(0, 0));
+----------------------------------------------------+
| st_azimuth(st_point(1.0, 0.0), st_point(0.0, 0.0)) |
+----------------------------------------------------+
| 4.71238898038469 |
+----------------------------------------------------+
SELECT st_azimuth(ST_Point(0, 0),ST_Point(1, 0));
+----------------------------------------------------+
| st_azimuth(st_point(0.0, 0.0), st_point(1.0, 0.0)) |
+----------------------------------------------------+
| 1.5707963267948966 |
+----------------------------------------------------+
SELECT st_azimuth(ST_Point(0, 0),ST_Point(0, 1));
+----------------------------------------------------+
| st_azimuth(st_point(0.0, 0.0), st_point(0.0, 1.0)) |
+----------------------------------------------------+
| 0 |
+----------------------------------------------------+
SELECT st_azimuth(ST_Point(-30, 0),ST_Point(150, 0));
+--------------------------------------------------------+
| st_azimuth(st_point(-30.0, 0.0), st_point(150.0, 0.0)) |
+--------------------------------------------------------+
| NULL |
+--------------------------------------------------------+