Orbit Shapes – ephemerista.coords.shapes

The shapes.py module.

This module provides several classes which provide different ways to define the shape of an orbit.

• Semi-major axis and eccentricity: SemiMajorAxisShape

• Radius pairs: RadiiShape

• Altitude pairs: AltitudesShape

Notes

The classes in this module are part of the ephemerista.coords.twobody.Keplerian data model for Keplerian orbits and should not be used directly.

pydantic model ephemerista.coords.shapes.AltitudesShape

Orbit shape based on apoapsis and periapsis altitude.

Fields:

• apoapsis_altitude (float)

• periapsis_altitude (float)

• shape_type (Literal['altitudes'])

field apoapsis_altitude: float [Required] (alias 'apoapsisAltitude')

The apoapsis altitude of the orbit [km]

Constraints:

• gt = 0

field periapsis_altitude: float [Required] (alias 'periapsisAltitude')

The periapsis altitude of the orbit [km]

Constraints:

• gt = 0

field shape_type: Literal['altitudes'] = 'altitudes' (alias 'type')

The type of the orbit shape

apoapsis_radius(mean_radius)

Return the apoapsis radius of the orbit in kilometers.

Return type:

float

eccentricity(mean_radius)

Return the eccentricity of the orbit.

Return type:

float

periapsis_radius(mean_radius)

Return the periapsis radius of the orbit in kilometers.

Return type:

float

semi_major_axis(mean_radius)

Return the semi-major axis of the orbit in kilometers.

Return type:

float

pydantic model ephemerista.coords.shapes.OrbitShape

Abstract base class for orbital shapes.

abstractmethod apoapsis_radius(mean_radius)

Return the apoapsis radius of the orbit in kilometers.

Parameters:

mean_radius (float) – Mean radius of the central body [km]

Return type:

float

Notes

The mean_radius parameter is not being used by the SemiMajorAxisShape and RadiiShape subclasses.

abstractmethod eccentricity(mean_radius)

Return the eccentricity of the orbit.

Parameters:

mean_radius (float) – Mean radius of the central body [km]

Return type:

float

Notes

The mean_radius parameter is not being used by the SemiMajorAxisShape and RadiiShape subclasses.

abstractmethod periapsis_radius(mean_radius)

Return the periapsis radius of the orbit in kilometers.

Parameters:

mean_radius (float) – Mean radius of the central body [km]

Return type:

float

Notes

The mean_radius parameter is not being used by the SemiMajorAxisShape and RadiiShape subclasses.

abstractmethod semi_major_axis(mean_radius)

Return the semi-major axis of the orbit in kilometers.

Parameters:

mean_radius (float) – Mean radius of the central body [km]

Return type:

float

Notes

The mean_radius parameter is not being used by the SemiMajorAxisShape and RadiiShape subclasses and can be set to zero.

pydantic model ephemerista.coords.shapes.RadiiShape

Orbit shape based on apoapsis and periapsis radius.

Fields:

• ra (float)

• rp (float)

• shape_type (Literal['radii'])

field ra: float [Required] (alias 'apoapsisRadius')

The apoapsis radius of the orbit [km]

Constraints:

• gt = 0

field rp: float [Required] (alias 'periapsisRadius')

The periapsis radius of the orbit [km]

Constraints:

• gt = 0

field shape_type: Literal['radii'] = 'radii' (alias 'type')

The type of the orbit shape

apoapsis_radius(mean_radius)

Return the apoapsis radius of the orbit in kilometers.

Return type:

float

eccentricity(mean_radius)

Return the eccentricity of the orbit.

Return type:

float

periapsis_radius(mean_radius)

Return the periapsis radius of the orbit in kilometers.

Return type:

float

semi_major_axis(mean_radius)

Return the semi-major axis of the orbit in kilometers.

Return type:

float

pydantic model ephemerista.coords.shapes.SemiMajorAxisShape

Orbit shape based on semi-major axis and eccentricity.

Fields:

• ecc (float)

• shape_type (Literal['semi_major'])

• sma (float)

field ecc: float [Required] (alias 'eccentricity')

Eccentricity of the orbit

field shape_type: Literal['semi_major'] = 'semi_major' (alias 'type')

The type of the orbit shape

field sma: float [Required] (alias 'semiMajorAxis')

Semi-major axis of the orbit [km]

apoapsis_radius(mean_radius)

Return the apoapsis radius of the orbit in kilometers.

Return type:

float

eccentricity(mean_radius)

Return the eccentricity of the orbit.

Return type:

float

periapsis_radius(mean_radius)

Return the periapsis radius of the orbit in kilometers.

Return type:

float

semi_major_axis(mean_radius)

Return the semi-major axis of the orbit in kilometers.

Return type:

float