Kepleriean orbital elements

Represent Keplerian element sets and convert between cartesian

Notes: * This class is used to represent Keplerian elements and convert between Cartesian coordinates * The class uses the semi-major axis (a), not the semiparameter * All angle units are radians * All length units are meters * All velocity units are meters / second

property satkit.kepler.eccentric_anomaly: float

Eccentric anomaly, radians

satkit.kepler.from_pv(vel: numpy.typing.ArrayLike[numpy.float64]) → kepler

Create Keplerian element set from input position and velocity vectors

Parameters:

• pos (npt.ArrayLike[np.float64]) – 3-element array representing position vector

• vel (npt.ArrayLike[np.float64]) – 3-element array representing velocity vector

Returns:

Keplerian element set object

Return type:

satkit.kepler

property satkit.kepler.mean_anomaly: float

Mean anomaly, radians

property satkit.kepler.mean_motion: float

Mean motion, radians / second

property satkit.kepler.period: float

Orbital period, seconds

satkit.kepler.propagate(dt: duration | float) → kepler

Propagate Keplerian element set by input duration

Parameters:

dt (duration | float) – Duration by which to propagate the Keplerian element set If float, value is seconds

Returns:

Keplerian element set object after propagation

Return type:

satkit.kepler

satkit.kepler.to_pv() → Tuple[numpy.typing.ArrayLike[numpy.float64], numpy.typing.ArrayLike[numpy.float64]]

Convert Keplerian element set to position and velocity vectors

Returns:

Tuple with two elements representing the position and velocity vectors

Return type:

tuple[npt.ArrayLike[np.float64], npt.ArrayLike[np.float64]]

property satkit.kepler.true_anomaly: float

True anomaly, radians