3.4. Circle #
A spherical circle is an area around a point, where all points inside the circle have a distance less than or equal to the radius of the circle. Use cases are:
sites on earth having a maximum distance from another site
round cluster or nebula on sky sphere
a position with an undirected position error
A circle is specified using a spherical point (spoint) and a
radius :
< point , radius >
Valid radius units are RAD,
DEG, and DMS. The
circle radius must be less than or equal to 90° and cannot
be less than zero.
Example 3.7. A circle around the North Pole with a radius of 5°.
sql> SELECT scircle '< (0d, 90d), 5d >';