ST_SunPosition

Signatures

GEOMETRY ST_SunPosition(POINT point);
GEOMETRY ST_SunPosition(POINT point, TIMESTAMP time);

Description

Compute the sun position, according a point location, and return a new 2D point which coordinate is defined as:

• x = sun azimuth direction along the horizon, in radians, measured from north to east,

• y = sun altitude above the horizon, in radians, e.g. 0 at the horizon and PI/2 at the zenith.

By default, the current time sun position is returned. Optionally, the user can specify another date using the time parameter.

The point coordinates have to be exprimed in the WGS84 projection system (lat / long)

Examples

At the current time:

SELECT ST_SunPosition('POINT(1 2)');
-- Answer: POINT (1.4378813602343208 0.4193351921603638) 

Or using the time parameter (e.g for May 26th 2010 at 15h35’26s) :

SELECT ST_SunPosition('POINT(1 2)', '2010-05-26 15:35:26')
-- Answer: POINT (5.403682948309358 1.0249420692671862)  

Use case

A specific use case, using ST_SunPosition and ST_GeometryShadow is avalaible HERE.

See also

• ST_GeometryShadow

• Source code