astro.state_2_classical_p#
- hohmannpy.astro.state_2_classical_p(position, velocity, grav_param=398600441800000.0)#
Parabolic version of
state_2_classical()which takes in the semi-latus rectum instead of the semi-major axis.For a parabolic orbit the semi-major axis is infinite. As a result computing the semi-latus rectum (and hence the orbital radius) from these is impossible and instead to define a parabolic orbit the semi-latus rectum must be defined directly. Note that for parabolic orbits only this is equivalent to the radius of periapsis.
- Parameters:
position (np.ndarray) – Position of the satellite in planet-centered inertial coordinates.
velocity (np.ndarray) – Velocity of the satellite in planet-centered inertial coordinates.
grav_param (float) – Gravitational parameter of the central body (defaults to that of the Earth in \(\text{m}^3/\text{s}^2\)).
- Returns:
sl_rectum (float) – Semi-latus rectum.
eccentricity (float) – Eccentricity.
raan (float) – Right ascension (longitude) of the ascending node.
argp (float) – Argument of periapsis.
inclination (float) – Inclination.
true_anomaly (float) – True anomaly.
grav_param (float) – Gravitational parameter of the central body (defaults to that of the Earth in \(\text{m}^3/\text{s}^2\)).
See also
state_2_classical()Standard version of this function which returns the semi-major axis instead of the semi-latus rectum.
Notes
The semi-latus rectum \(p\) is computed from the eccentricity \(e\) and semi-major axis \(a\) via
\[p = a (1 - e^2)\]For a parabolic orbit this results in the indeterminate form \(p = \infty (0)\) from which the semi-latus rectum can not be recovered.