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XYZ File Format and Orbit

Posted: 18.05.2005, 20:57
by rolandd
Is the XYZ file format only relative to the sun or can it be relative to any object? For example, I wish to have an object rotate around a planet using an XYZ file.

In addition, using EllipticalOrbit, is it possible to have an object maintain a constant latitute for an orbit other than over the equator? For example, can I have an object rotate in an orbit around one of the poles at a constant latitude?

All The Best,
Roland

Posted: 18.05.2005, 23:37
by selden
xyz trajectories are relative to the object being orbited as specified in the SSC file.

For example,

Code: Select all

"spacecraft" "Sol" {
   SampledOrbit "spacecraft.xyz" }

would require a heliocentric trajectory, while

Code: Select all

"spacecraft" "Sol/Earth" {
   SampledOrbit "spacecraft.xyz" }

would require one centered on the Earth.

Elliptical orbits are centered around the center of the body being orbited. You'd have to define an invisible body that's in an orbit around the planet but with an "infinite" orbital period so that it can be placed at an appropriate latitude and not move. Then your object would orbit that body.

See http://www.lepp.cornell.edu/~seb/celest ... s-130.html
for an example (although it has both bodies not moving).


Does this help?

Posted: 19.05.2005, 14:20
by rolandd
Selden,

Thanks for your direction, this has been very helpful.

Roland