Voir la source de Tutorials 4.5.1 Orbits

== What is an orbit ? ==

An orbit is defined with a <font color=#FF0000>date</font>, a <font color=#FF0000>frame</font> then <font color=#FF0000>orbital parameters</font>; in the example below, we will use keplerian parameters ...
* semi major axis
* eccentricity
* inclination
* perigee argument
* right ascension of the ascending node
* anomaly (mean, true, eccentric)

Note that it is mandatory to set the "Mu" value (gravitational constant) for both reasons :
# to be able to convert keplerian parameters to cartesian ones
# to propagate this orbit using the keplerian motion (considering only the central term) (for more sophisticated propagations (analytical or numerical ones) see specific tutorials).

'''Code example:''' [[CreateKeplerianOrbit_4.5.1|create a Keplerian orbit]]

== Orbital parameters ==

Rather than to set directly orbital parameters when creating an orbit (see previous tutorial), it is possible to go through an intermediate object including these orbital parameters.

Then to create an orbit, we will have to set the <font color=#FF0000>date</font>, the <font color=#FF0000>frame</font> ... and this object.

Moreover, the advantage of this sublevel is to treat parameters conversions without considering a whole orbit (for example, to convert <font color=#FF0000>keplerian</font> parameters in <font color=#FF0000>cartesian</font> ones, it is not necessary to use a <font color=#FF0000>date</font> or a <font color=#FF0000>frame</font>).

'''Code example:''' [[CreateKeplerianOrbitUsingParameters_4.5.1|create a Keplerian orbit using parameters]]

== Reentry parameters ==

In case of atmospheric reentry trajectories, it could be useful to get specific "reentry parameters" defined in an inertial or even rotating frame. The following code gives some examples ...

'''Code example:''' [[Reentryparameters_4.5.1|Reentry parameters]]

== Orbital parameters conversions ==

As explained in the previous tutorial, it is possible to make a lot of conversion between different orbital parameters formats. The following code gives some examples ...

'''Code example:''' [[ParametersConversions_4.5.1|orbital parameters conversions]]

[[Category:Tutorials 4.5.1]]