poliastro2.core.ephem¶
Functions
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Interpolates ephemerides data. |
Classes
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Time history of position and velocity of some object at particular epochs. |
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- class poliastro2.core.ephem.Ephem(coordinates, epochs, plane)¶
Time history of position and velocity of some object at particular epochs.
Instead of creating Ephem objects directly, use the available classmethods.
- Parameters:
coordinates (astropy.coordinates.CartesianRepresentation) – Coordinates with velocities.
epochs (astropy.time.Time) – Epochs corresponding to the coordinates.
plane (Planes) – Reference plane of the coordinates.
- property epochs¶
Epochs at which the ephemerides was originally sampled.
- classmethod from_body(body, epochs, *, attractor=None, plane=Planes.EARTH_EQUATOR)¶
Return Ephem for a SolarSystemPlanet at certain epochs.
- Parameters:
body (SolarSystemPlanet) – Body.
epochs (Time) – Epochs to sample the body positions.
attractor (SolarSystemPlanet, optional) – Body to use as central location, if not given the Solar System Barycenter will be used.
plane (Planes, optional) – Fundamental plane of the frame, default to Earth Equator.
- classmethod from_horizons(name, epochs, *, attractor=None, plane=Planes.EARTH_EQUATOR, id_type=None)¶
Return Ephem for an object using JPLHorizons module of Astroquery.
- Parameters:
name (str) – Name of the body to query for.
epochs (Time) – Epochs to sample the body positions.
attractor (SolarSystemPlanet, optional) – Body to use as central location, if not given the Solar System Barycenter will be used.
plane (Planes, optional) – Fundamental plane of the frame, default to Earth Equator.
id_type (NoneType or str, optional) – Use “smallbody” for Asteroids and Comets and None (default) to first search for Planets and Satellites.
- classmethod from_orbit(orbit, epochs, plane=Planes.EARTH_EQUATOR)¶
Return Ephem from an Orbit at certain epochs.
- Parameters:
orbit (Orbit) – Orbit.
epochs (Time) – Epochs to sample the orbit positions.
plane (Planes, optional) – Fundamental plane of the frame, default to Earth Equator.
- property plane¶
Reference plane of the ephemerides.
- rv(epochs=None, **kwargs)¶
Position and velocity vectors at given epochs.
- Parameters:
epochs (Time, optional) – Epochs to sample the ephemerides, default to now.
**kwargs – Extra kwargs for interpolation method.
- sample(epochs=None, *, interpolator=<poliastro2.core.ephem.SplineInterpolator object>)¶
Returns coordinates at specified epochs.
- Parameters:
epochs (Time, optional) – Epochs to sample the ephemerides, if not given the original one from the object will be used.
interpolator (BaseInterpolator, optional) – Interpolation method to use for epochs outside of the original ones, default to splines.
- Returns:
Sampled coordinates with velocities.
- Return type:
CartesianRepresentation
- class poliastro2.core.ephem.SplineInterpolator(kind='cubic')¶
- interpolate(epochs, reference_epochs, coordinates)¶
- poliastro2.core.ephem._get_destination_frame(attractor, plane, epochs)¶
- poliastro2.core.ephem.build_ephem_interpolant(body, epochs, attractor=((None, <Quantity 1.32712442e+20 m3 / s2>, 'Sun', '☉', <Quantity 6.957e+08 m>, <Quantity 0. km>, <Quantity 0. km>, <Quantity 25.38 d>, <Quantity 2.2e-07>, <Quantity 0.>, <Quantity 1.98840987e+30 kg>, <Quantity 0. km>), <Quantity 3.98600442e+14 m3 / s2>, 'Earth', '♁', <Quantity 6378136.6 m>, <Quantity 6356751.9 m>, <Quantity 6371008.4 m>, <Quantity 0.9972698 d>, <Quantity 0.00108263>, <Quantity -2.53266132e-06>, <Quantity 5.97216787e+24 kg>, <Quantity 1.49597871e+08 km>))¶
Interpolates ephemerides data.
- Parameters:
body (Body) – Source body.
epochs (Time) – Array of time values, can be generated with poliastro.util.time_range.
attractor (Body, optional) – Attractor, default to Earth.
- Returns:
interpolant – Interpolant function that receives time increment in seconds since the initial epoch.
- Return type:
callable