tbw
A commonly used task is a coordinate transformation. With the parameters of a new coordinate system (plane) relative to an old one,
| Ω | longitude of the ascending node | angle between line of nodes and the zero point of longitude in the old plane. |
| ω | argument of pericenter | the angle from the ascending node to the position in the new plane. |
| i | inclination | angle between the new plane and the old plane. |
you can do a transformation of an object
object from an old into a new coordinate
system using:
sinverse( object, strans( 'ω, i, Ω' ) )
Otherwise, for a transformation of an object
object from the new into the old
coordinate system, use transform:
stransform( object, strans( 'ω, i, Ω' ) )
Example 51. Perihel and aphel coordinates of a comet orbit
We are assuming the orbital elements of a comet are Ω=30°, i=60° and ω=90°. We get the spherical position of perihel and aphel with:
mysql> SET sphere_outmode="DEG"; Query OK, 0 rows affected (0.02 sec) mysql> SELECT sstr( stransform( spoint( '(0,0)' ), strans( '90d,60d,30d' ) ) ) AS perihel; +--------------+ | perihel | +--------------+ | (120d , 60d) | +--------------+ 1 row in set (0.01 sec) mysql> SELECT sstr( stransform( spoint( '(180d,0)' ), strans( '90d,60d,30d' ) ) ) AS aphel; +---------------+ | aphel | +---------------+ | (300d , -60d) | +---------------+ 1 row in set (0.01 sec)