CL_eph_planet

Description

• Computes planets position and velocity vectors relative to the ecliptic of date (EOD)

  The origin of the frame is the Sun.

  Available planets are "Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus" and "Neptune"

  The model used can optionaly be modified:

  - model = "med": VSOP87 "med" model is used.

  - model = "high": VSOP87 "high" model is used.

  - model = "full": VSOP87 "full" model is used.

• Notes:

  - Chosen model greatly affects the time and memory consumed by the function

  - Planet names are case sensitive

• See Reference frames for more details on the EOD frame, and Ephemerides for more details on the models.

Parameters

planet:

(string) Name of planet ("Mercury","Venus","Earth","Mars","Jupiter","Saturn","Uranus" or "Neptune") (1x1)

cjd:

Modified (1950.0) julian day (Time scale: TREF) (1xN)

tt_tref:

(optional) TT-TREF [seconds]. Default is %CL_TT_TREF. (1xN or 1x1)

model :

(optional, string) Name of the model. "med", "high" or "full". Default is "med". (1x1)

pos :

Planet position vector in output frame [m] (3xN)

vel :

Planet velocity vector in output frame [m/s] (3xN)

Bibliography

• Planetary Theories in rectangular and spherical variables: VSOP87 solution. Bretagnon P., Francou G.

• Astronomical Algorithms J.Meeus, Appendix II

Authors

• CNES - DCT/SB

See also

• CL_eph_de405

Examples

cjd = CL_dat_cal2cjd(2010,02,03,05,35,25); // Default = standard precision pos_mars = CL_eph_planet("Mars", cjd) // Higher precision [pos_uranus_EOD,vel_uranus_EOD] = CL_eph_planet("Uranus", cjd, model = "high"); // Maximum precision [pos_saturn_EOD,vel_saturn_EOD] = CL_eph_planet("Saturn", cjd, model = "full");