Force Model Configuration¶

Configuration classes for numerical orbit propagation force models. ForceModelConfig provides factory methods for common configurations and allows customization of gravity, atmospheric drag, solar radiation pressure, third-body perturbations, and solid Earth and ocean tides.

Note

For conceptual explanations and usage examples, see Force Models in the User Guide. For CentralBody, lunar_default()/cislunar_default()/mars_default(), and state_in_frame, see Cislunar and Lunar Propagation and Propagation Around Other Central Bodies.

ForceModelConfig¶

ForceModelConfig ¶

ForceModelConfig(gravity: GravityConfiguration = None, drag: DragConfiguration = None, srp: SolarRadiationPressureConfiguration = None, third_body: ThirdBodyConfiguration | ThirdBody | list = None, relativity: bool = False, mass: ParameterSource = None, frame_transform: FrameTransformationModel = None, tides: Any = None)

Force model configuration for numerical orbit propagation.

Defines all perturbation forces to be included: gravity, drag, SRP, third-body, relativity.

Parameters:

Name	Type	Description	Default
`gravity`	`GravityConfiguration`	Gravity model configuration. Default is point mass gravity.	`None`
`drag`	`DragConfiguration`	Atmospheric drag configuration. Default is None (disabled).	`None`
`srp`	`SolarRadiationPressureConfiguration`	Solar radiation pressure configuration. Default is None (disabled).	`None`
`third_body`	`ThirdBodyConfiguration \| ThirdBody \| list`	Third-body perturbation entries; a single entry or a list mixing ThirdBody and ThirdBodyConfiguration values. Default is None (disabled).	`None`
`relativity`	`bool`	Enable relativistic corrections. Default is False.	`False`
`mass`	`ParameterSource`	Spacecraft mass source. Default is None.	`None`
`frame_transform`	`FrameTransformationModel`	ECI-to-body-fixed rotation used by every body-fixed force term. Defaults to `FULL_EARTH_ROTATION`.	`None`

Attributes:

Name	Type	Description
`gravity`	`GravityConfiguration`	Gravity model configuration
`drag`	`DragConfiguration or None`	Atmospheric drag configuration
`srp`	`SolarRadiationPressureConfiguration or None`	Solar radiation pressure configuration
`third_body`	`list[ThirdBodyConfiguration] or None`	Third-body perturbation entries
`relativity`	`bool`	Enable relativistic corrections
`mass`	`ParameterSource or None`	Spacecraft mass source
`frame_transform`	`FrameTransformationModel`	ECI-to-body-fixed rotation model

Example

import brahe as bh

# Create with explicit parameters
config = bh.ForceModelConfig(
    gravity=bh.GravityConfiguration(degree=20, order=20),
    relativity=True,
)

# Or use convenience class methods
config = bh.ForceModelConfig.default()
config = bh.ForceModelConfig.two_body()

Initialize instance.

central_body `property` ¶

central_body: Any

Get the central body this configuration propagates relative to.

drag `property` ¶

drag: Any

Get the drag configuration (None if disabled).

frame_transform `property` ¶

frame_transform: Any

Get the ECI-to-body-fixed frame transformation model.

gravity `property` ¶

gravity: Any

Get the gravity configuration.

mass `property` ¶

mass: Any

Get the mass parameter source (None if not required).

relativity `property` ¶

relativity: Any

Get whether relativistic corrections are enabled.

srp `property` ¶

srp: Any

Get the solar radiation pressure configuration (None if disabled).

third_body `property` ¶

third_body: Any

Get the third-body perturbation entries (None if disabled).

tides `property` ¶

tides: Any

Get the tidal correction configuration (None if disabled).

cislunar_default `builtin` ¶

cislunar_default() -> ForceModelConfig

Create a configuration suitable for cislunar propagation about the Earth-Moon barycenter.

Uses point mass gravity (the barycenter has no mass of its own), no drag, SRP occulted by Earth and the Moon, and Earth/Moon/Sun third-body perturbations (DE440s ephemerides). Requires parameter vector: [mass, , , srp_area, Cr]

Returns:

Name	Type	Description
`ForceModelConfig`	`ForceModelConfig`	Configuration with the Earth-Moon barycenter as the central body.

conservative_forces `builtin` ¶

conservative_forces() -> ForceModelConfig

Create a conservative forces configuration (gravity + third-body + relativity, no drag/SRP).

default `builtin` ¶

default() -> ForceModelConfig

Create a default force model configuration.

Includes: - 20x20 EGM2008 gravity - Harris-Priester atmospheric drag - Solar radiation pressure with conical eclipse - Sun and Moon third-body perturbations

Requires parameter vector: [mass, drag_area, Cd, srp_area, Cr]

earth_gravity `builtin` ¶

earth_gravity() -> ForceModelConfig

Create an Earth gravity-only configuration (no drag, SRP, or third-body).

Uses 20x20 EGM2008 gravity. No parameter vector required.

for_body `builtin` ¶

for_body(central_body: CentralBody, gravity: GravityConfiguration, drag: DragConfiguration = None, srp: SolarRadiationPressureConfiguration = None, third_body: ThirdBodyConfiguration | ThirdBody | list = None, relativity: bool = False, mass: ParameterSource = None) -> ForceModelConfig

Create a force model configuration for a specific central body.

Convenience constructor that fills in frame_transform with its default (FrameTransformationModel.FULL_EARTH_ROTATION) so callers only need to specify the options that vary per central body. Does not validate the resulting configuration -- call validate() to check that the chosen options are compatible with central_body.

Parameters:

Name	Type	Description	Default
`central_body`	`CentralBody`	Body the orbit is propagated relative to.	required
`gravity`	`GravityConfiguration`	Gravity model configuration.	required
`drag`	`DragConfiguration`	Atmospheric drag configuration.	`None`
`srp`	`SolarRadiationPressureConfiguration`	Solar radiation pressure configuration.	`None`
`third_body`	`ThirdBodyConfiguration \| ThirdBody \| list`	Third-body perturbation entries; a single entry or a list mixing ThirdBody and ThirdBodyConfiguration values.	`None`
`relativity`	`bool`	Enable relativistic corrections. Default is False.	`False`
`mass`	`ParameterSource`	Spacecraft mass source.	`None`

Returns:

Name	Type	Description
`ForceModelConfig`	`ForceModelConfig`	A force model configuration for `central_body`.

geo_default `builtin` ¶

geo_default() -> ForceModelConfig

Create a configuration suitable for GEO satellites.

Includes SRP and third-body perturbations, omits drag. Requires parameter vector: [mass, , , srp_area, Cr]

high_fidelity `builtin` ¶

high_fidelity() -> ForceModelConfig

Create a high-fidelity force model configuration.

Includes: - 120x120 EGM2008 gravity - NRLMSISE-00 atmospheric model - SRP with conical eclipse - Sun, Moon, and all planets (DE440s ephemerides) - Relativistic corrections - Solid Earth tides with frequency-dependent corrections and the solid pole tide - Ocean tides (FES2004, 30x30) with admittance and the ocean pole tide; requires a one-time cached download of the IERS FES2004 coefficient file

Requires parameter vector: [mass, drag_area, Cd, srp_area, Cr]

leo_default `builtin` ¶

leo_default() -> ForceModelConfig

Create a configuration suitable for LEO satellites.

Includes drag and higher-order gravity, plus SRP and third-body. Requires parameter vector: [mass, drag_area, Cd, srp_area, Cr]

lunar_default `builtin` ¶

lunar_default() -> ForceModelConfig

Create a configuration suitable for propagation about the Moon.

Uses 50x50 GRGM660PRIM lunar gravity, no drag, SRP occulted by the Moon and Earth, and Earth/Sun third-body perturbations (DE440s ephemerides). Requires parameter vector: [mass, , , srp_area, Cr]

Returns:

Name	Type	Description
`ForceModelConfig`	`ForceModelConfig`	Configuration with the Moon as the central body.

mars_default `builtin` ¶

mars_default() -> ForceModelConfig

Create a configuration suitable for propagation about Mars.

Uses 50x50 GMM-2B Mars gravity, exponential atmospheric drag, SRP occulted by Mars, and Sun third-body perturbations (DE440s ephemerides). Requires parameter vector: [mass, drag_area, Cd, srp_area, Cr]

Returns:

Name	Type	Description
`ForceModelConfig`	`ForceModelConfig`	Configuration with Mars as the central body.

requires_params `method descriptor` ¶

requires_params() -> Any

Check if this configuration requires a parameter vector.

two_body `builtin` ¶

two_body() -> ForceModelConfig

Create a two-body (point mass) gravity configuration.

Uses only central body gravity with no perturbations. Produces results equivalent to Keplerian propagation. No parameter vector required.

validate `method descriptor` ¶

validate() -> None

Validate that this configuration's options are compatible with its central body.

This method is called automatically at propagator construction; it may also be called explicitly ahead of time on a standalone configuration for early feedback.

Returns:

Name	Type	Description
`None`	`None`	If the configuration is internally consistent.

Raises:

Type	Description
`RuntimeError`	If the configuration is internally inconsistent (naming both the offending option and the central body).

Central Body¶

CentralBody ¶

CentralBody()

The central body an orbit is propagated relative to.

Earth, Moon, and Mars are built in because they have dedicated named inertial/fixed frame pairs elsewhere in brahe (GCRF/ITRF, LCI/LFPA, MCI/MCMF). EMB and SSB are the Earth-Moon and Solar System barycenters -- useful as propagation origins for heliocentric or cislunar trajectories, but they have no physical radius, spin, or fixed frame. Any other body is constructed via CentralBody.Custom(...) or CentralBody.from_naif_id(...).

Example

import brahe as bh

earth = bh.CentralBody.Earth
moon = bh.CentralBody.Moon
enceladus = bh.CentralBody.from_naif_id(602)

Initialize instance.

EMB `class-attribute` ¶

EMB: Any = CentralBody.EMB

The central body an orbit is propagated relative to.

Earth, Moon, and Mars are built in because they have dedicated named inertial/fixed frame pairs elsewhere in brahe (GCRF/ITRF, LCI/LFPA, MCI/MCMF). EMB and SSB are the Earth-Moon and Solar System barycenters -- useful as propagation origins for heliocentric or cislunar trajectories, but they have no physical radius, spin, or fixed frame. Any other body is constructed via CentralBody.Custom(...) or CentralBody.from_naif_id(...).

Example

import brahe as bh

earth = bh.CentralBody.Earth
moon = bh.CentralBody.Moon
enceladus = bh.CentralBody.from_naif_id(602)

Earth `class-attribute` ¶

Earth: Any = CentralBody.Earth

The central body an orbit is propagated relative to.

Earth, Moon, and Mars are built in because they have dedicated named inertial/fixed frame pairs elsewhere in brahe (GCRF/ITRF, LCI/LFPA, MCI/MCMF). EMB and SSB are the Earth-Moon and Solar System barycenters -- useful as propagation origins for heliocentric or cislunar trajectories, but they have no physical radius, spin, or fixed frame. Any other body is constructed via CentralBody.Custom(...) or CentralBody.from_naif_id(...).

Example

import brahe as bh

earth = bh.CentralBody.Earth
moon = bh.CentralBody.Moon
enceladus = bh.CentralBody.from_naif_id(602)

Mars `class-attribute` ¶

Mars: Any = CentralBody.Mars

The central body an orbit is propagated relative to.

Earth, Moon, and Mars are built in because they have dedicated named inertial/fixed frame pairs elsewhere in brahe (GCRF/ITRF, LCI/LFPA, MCI/MCMF). EMB and SSB are the Earth-Moon and Solar System barycenters -- useful as propagation origins for heliocentric or cislunar trajectories, but they have no physical radius, spin, or fixed frame. Any other body is constructed via CentralBody.Custom(...) or CentralBody.from_naif_id(...).

Example

import brahe as bh

earth = bh.CentralBody.Earth
moon = bh.CentralBody.Moon
enceladus = bh.CentralBody.from_naif_id(602)

Moon `class-attribute` ¶

Moon: Any = CentralBody.Moon

The central body an orbit is propagated relative to.

Earth, Moon, and Mars are built in because they have dedicated named inertial/fixed frame pairs elsewhere in brahe (GCRF/ITRF, LCI/LFPA, MCI/MCMF). EMB and SSB are the Earth-Moon and Solar System barycenters -- useful as propagation origins for heliocentric or cislunar trajectories, but they have no physical radius, spin, or fixed frame. Any other body is constructed via CentralBody.Custom(...) or CentralBody.from_naif_id(...).

Example

import brahe as bh

earth = bh.CentralBody.Earth
moon = bh.CentralBody.Moon
enceladus = bh.CentralBody.from_naif_id(602)

SSB `class-attribute` ¶

SSB: Any = CentralBody.SSB

The central body an orbit is propagated relative to.

Earth, Moon, and Mars are built in because they have dedicated named inertial/fixed frame pairs elsewhere in brahe (GCRF/ITRF, LCI/LFPA, MCI/MCMF). EMB and SSB are the Earth-Moon and Solar System barycenters -- useful as propagation origins for heliocentric or cislunar trajectories, but they have no physical radius, spin, or fixed frame. Any other body is constructed via CentralBody.Custom(...) or CentralBody.from_naif_id(...).

Example

import brahe as bh

earth = bh.CentralBody.Earth
moon = bh.CentralBody.Moon
enceladus = bh.CentralBody.from_naif_id(602)

Custom `staticmethod` ¶

Custom(name: str, naif_id: int, gm: float, radius: float = None, omega: Union[ndarray, Sequence] = None, fixed_frame: ReferenceFrame = None) -> CentralBody

Construct a user-defined central body.

Parameters:

Name	Type	Description	Default
`name`	`str`	Human-readable name (e.g. `"Enceladus"`).	required
`naif_id`	`int`	NAIF ID of the body.	required
`gm`	`float`	Gravitational parameter. Units: (m^3/s^2)	required
`radius`	`float`	Mean or equatorial radius, if known. Units: (m)	`None`
`omega`	`ndarray or list`	Body-fixed axial spin vector, if known. Units: (rad/s)	`None`
`fixed_frame`	`ReferenceFrame`	Body-fixed reference frame, required for spherical-harmonic gravity and body-fixed rotations.	`None`

Returns:

Name	Type	Description
`CentralBody`	`CentralBody`	A user-defined central body.

fixed_frame `method descriptor` ¶

fixed_frame() -> ReferenceFrame

Body-fixed reference frame of this body, if one is defined.

Returns:

Type	Description
`ReferenceFrame`	ReferenceFrame or None: `ITRF` for `Earth`, `LFPA` for `Moon`, `MCMF` for `Mars`,
`ReferenceFrame`	`None` for `EMB`/`SSB`, and `custom.fixed_frame` for `Custom` bodies.

from_naif_id `staticmethod` ¶

from_naif_id(naif_id: int) -> CentralBody

Construct a CentralBody from a NAIF ID.

399, 301, 4/499, 3, and 0 map to the built-in Earth, Moon, Mars, EMB, and SSB variants respectively. A fixed table of other commonly used bodies maps to a pre-populated Custom variant.

Parameters:

Name	Type	Description	Default
`naif_id`	`int`	NAIF ID of the body.	required

Returns:

Name	Type	Description
`CentralBody`	`CentralBody`	The corresponding central body.

Raises:

Type	Description
`ValueError`	If `naif_id` is not a built-in body or in the embedded table.

gm `method descriptor` ¶

gm() -> float

Gravitational parameter of the central body.

Returns:

Name	Type	Description
`float`	`float`	Gravitational parameter. Units: (m^3/s^2). `0.0` for the `EMB` and `SSB` barycenters.

inertial_frame `method descriptor` ¶

inertial_frame() -> ReferenceFrame

ICRF-aligned inertial reference frame centered on this body.

Returns:

Name	Type	Description
`ReferenceFrame`	`ReferenceFrame`	`GCRF` for `Earth`, `LCI` for `Moon`, `MCI` for `Mars`, `EMBI`
	`ReferenceFrame`	for `EMB`, `SSBI` for `SSB`, and `BodyCenteredICRF(naif_id)` for `Custom` bodies.

is_barycenter `method descriptor` ¶

is_barycenter() -> bool

Whether this central body is a barycenter (EMB or SSB).

Returns:

Name	Type	Description
`bool`	`bool`	`True` for `EMB`/`SSB`, `False` otherwise.

naif_id `method descriptor` ¶

naif_id() -> int

NAIF ID of the central body.

Returns:

Name	Type	Description
`int`	`int`	NAIF ID.

omega_vector `method descriptor` ¶

omega_vector() -> ndarray

Body-fixed axial spin vector of the central body.

Returns:

Type	Description
`ndarray`	numpy.ndarray or None: Spin vector expressed in the body's inertial frame, if
`ndarray`	known. Units: (rad/s). `None` for the `EMB`/`SSB` barycenters and for `Custom`
`ndarray`	bodies unless `omega` was set explicitly.

radius `method descriptor` ¶

radius() -> float

Mean or equatorial radius of the central body.

Returns:

Type	Description
`float`	float or None: Radius, if known. Units: (m). `None` for the `EMB` and `SSB` barycenters.

Configuration Components¶

GravityConfiguration ¶

GravityConfiguration(degree: int = None, order: int = None, model_type: GravityModelType = None, use_global: bool = False, parallel: ParallelMode = None)

Gravity model configuration.

Specifies the gravity model: point mass or spherical harmonic expansion.

Parameters:

Name	Type	Description	Default
`degree`	`int`	Maximum degree of spherical harmonic expansion. If None, uses point mass gravity.	`None`
`order`	`int`	Maximum order of spherical harmonic expansion. If None, uses point mass gravity.	`None`
`model_type`	`GravityModelType`	Gravity model to use. Defaults to EGM2008_120.	`None`
`use_global`	`bool`	If True, use global gravity model. Defaults to False.	`False`
`parallel`	`ParallelMode`	Parallelization mode for the spherical-harmonic acceleration computation. Defaults to Auto.	`None`

Example

import brahe as bh

# Simple two-body point mass gravity (default)
gravity = bh.GravityConfiguration()

# Spherical harmonic with 20x20 degree/order
gravity = bh.GravityConfiguration(degree=20, order=20)

# Spherical harmonic with specific model
gravity = bh.GravityConfiguration(
    degree=20, order=20, model_type=bh.GravityModelType.GGM05S
)

# Alternative: use class methods
gravity = bh.GravityConfiguration.point_mass()
gravity = bh.GravityConfiguration.spherical_harmonic(degree=20, order=20)
gravity = bh.GravityConfiguration.earth_zonal(bh.ZonalHarmonicsDegree.J6)

Initialize instance.

earth_zonal `builtin` ¶

earth_zonal(degree: ZonalHarmonicsDegree) -> GravityConfiguration

Create an Earth zonal-only gravity configuration (J_2..=J_n, m=0).

Equivalent to spherical_harmonic with m = 0 against the packaged Earth gravity model, but evaluated via an explicit closed-form expansion that the compiler can vectorise — ~50% faster for the same axially-symmetric expansion. Earth-specific because the J_n coefficients and reference radius are baked into the implementation.

Parameters:

Name	Type	Description	Default
`degree`	`ZonalHarmonicsDegree`	Maximum zonal degree (J_2 through J_6).	required

Returns:

Name	Type	Description
`GravityConfiguration`	`GravityConfiguration`	Earth zonal gravity.

Example

import brahe as bh

gravity = bh.GravityConfiguration.earth_zonal(bh.ZonalHarmonicsDegree.J6)

get_degree `method descriptor` ¶

get_degree() -> int

Get the degree (for spherical harmonic).

Returns:

Type	Description
`int`	int or None: Degree if spherical harmonic, None otherwise.

get_earth_zonal_degree `method descriptor` ¶

get_earth_zonal_degree() -> ZonalHarmonicsDegree

Get the zonal degree (for Earth zonal gravity).

Returns:

Type	Description
`ZonalHarmonicsDegree`	ZonalHarmonicsDegree or None: Zonal degree if Earth zonal gravity, None otherwise.

get_order `method descriptor` ¶

get_order() -> int

Get the order (for spherical harmonic).

Returns:

Type	Description
`int`	int or None: Order if spherical harmonic, None otherwise.

get_parallel `method descriptor` ¶

get_parallel() -> ParallelMode

Get the parallel mode (for spherical harmonic).

Returns:

Type	Description
`ParallelMode`	ParallelMode or None: Parallel mode if spherical harmonic, None otherwise.

is_earth_zonal `method descriptor` ¶

is_earth_zonal() -> Any

Check if this is Earth zonal gravity.

is_point_mass `method descriptor` ¶

is_point_mass() -> Any

Check if this is point mass gravity.

is_spherical_harmonic `method descriptor` ¶

is_spherical_harmonic() -> Any

Check if this is spherical harmonic gravity.

point_mass `builtin` ¶

point_mass() -> GravityConfiguration

Create a point mass gravity configuration.

Returns:

Name	Type	Description
`GravityConfiguration`	`GravityConfiguration`	Point mass (two-body) gravity.

spherical_harmonic `builtin` ¶

spherical_harmonic(degree: int, order: int, model_type: GravityModelType = None, use_global: bool = False, parallel: ParallelMode = None) -> GravityConfiguration

Create a spherical harmonic gravity configuration.

Parameters:

Name	Type	Description	Default
`degree`	`int`	Maximum degree of expansion.	required
`order`	`int`	Maximum order of expansion.	required
`model_type`	`GravityModelType`	Gravity model to use. Defaults to EGM2008_120.	`None`
`use_global`	`bool`	If True, use global gravity model. Defaults to False.	`False`
`parallel`	`ParallelMode`	Parallelization mode for the spherical-harmonic acceleration computation. Defaults to Auto.	`None`

Returns:

Name	Type	Description
`GravityConfiguration`	`GravityConfiguration`	Spherical harmonic gravity.

Example

import brahe as bh

# Default (EGM2008)
gravity = bh.GravityConfiguration.spherical_harmonic(degree=20, order=20)

# With specific model
gravity = bh.GravityConfiguration.spherical_harmonic(
    degree=20, order=20, model_type=bh.GravityModelType.GGM05S
)

zero `builtin` ¶

zero() -> GravityConfiguration

Create a configuration with no gravity term from the propagation center. For barycentric propagation centers (CentralBody.EMB, CentralBody.SSB), which have no mass of their own: every gravitational force enters through the third-body entries.

Returns:

Name	Type	Description
`GravityConfiguration`	`GravityConfiguration`	No central gravity term.

DragConfiguration ¶

DragConfiguration(model: AtmosphericModel, area: ParameterSource, cd: ParameterSource, body: CentralBody = None)

Atmospheric drag configuration.

Defines the atmospheric model and drag parameters. The optional body attributes the drag to a body other than the propagation's central body: density and relative wind are then evaluated at the object's state relative to that body (e.g. Earth drag on an EMB-centered cislunar trajectory).

Parameters:

Name	Type	Description	Default
`model`	`AtmosphericModel`	Atmospheric density model.	required
`area`	`ParameterSource`	Drag cross-sectional area source [m²].	required
`cd`	`ParameterSource`	Drag coefficient source (dimensionless).	required
`body`	`CentralBody`	Body whose atmosphere produces the drag. Defaults to None, meaning the propagation's central body.	`None`

Attributes:

Name	Type	Description
`model`	`AtmosphericModel`	Atmospheric density model
`area`	`ParameterSource`	Drag area source
`cd`	`ParameterSource`	Drag coefficient source
`body`	`CentralBody or None`	Attributed drag body

Example

import brahe as bh

drag = bh.DragConfiguration(
    model=bh.AtmosphericModel.HARRIS_PRIESTER,
    area=bh.ParameterSource.parameter_index(1),
    cd=bh.ParameterSource.value(2.2)
)

# Earth-attributed drag for an EMB-centered propagation
cislunar_drag = bh.DragConfiguration(
    model=bh.AtmosphericModel.NRLMSISE00,
    area=bh.ParameterSource.value(10.0),
    cd=bh.ParameterSource.value(2.2),
    body=bh.CentralBody.Earth,
)

Initialize instance.

area `property` ¶

area: Any

Get the drag area parameter source.

body `property` ¶

body: Any

Get the attributed drag body (None = the propagation's central body).

cd `property` ¶

cd: Any

Get the drag coefficient parameter source.

model `property` ¶

model: Any

Get the atmospheric model.

SolarRadiationPressureConfiguration ¶

SolarRadiationPressureConfiguration(area: ParameterSource, cr: ParameterSource, eclipse_model: EclipseModel, occulting_bodies: list[OccultingBody] = None)

Solar radiation pressure configuration.

Defines the SRP parameters and eclipse model.

Parameters:

Name	Type	Description	Default
`area`	`ParameterSource`	SRP cross-sectional area source [m²].	required
`cr`	`ParameterSource`	Coefficient of reflectivity source (dimensionless).	required
`eclipse_model`	`EclipseModel`	Eclipse model for shadow effects.	required
`occulting_bodies`	`list[OccultingBody]`	Bodies whose shadow may occult the sun. Defaults to `[OccultingBody.Earth]`.	`None`

Attributes:

Name	Type	Description
`area`	`ParameterSource`	SRP area source
`cr`	`ParameterSource`	Reflectivity coefficient source
`eclipse_model`	`EclipseModel`	Eclipse model
`occulting_bodies`	`list[OccultingBody]`	Bodies whose shadow may occult the sun

Example

import brahe as bh

srp = bh.SolarRadiationPressureConfiguration(
    area=bh.ParameterSource.parameter_index(3),
    cr=bh.ParameterSource.parameter_index(4),
    eclipse_model=bh.EclipseModel.CONICAL
)

Initialize instance.

area `property` ¶

area: Any

Get the SRP area parameter source.

cr `property` ¶

cr: Any

Get the coefficient of reflectivity parameter source.

eclipse_model `property` ¶

eclipse_model: Any

Get the eclipse model.

occulting_bodies `property` ¶

occulting_bodies: Any

Get the bodies whose shadow may occult the sun.

ThirdBodyConfiguration ¶

ThirdBodyConfiguration(body: ThirdBody, ephemeris_source: EphemerisSource = None, gravity: GravityConfiguration = None)

Configuration for a single third-body perturber.

Pairs a perturbing body with its ephemeris source and the gravity model used for its perturbation (point-mass by default; a spherical-harmonic or Earth-zonal field evaluates at the object's position relative to the body).

Parameters:

Name	Type	Description	Default
`body`	`ThirdBody`	The perturbing body.	required
`ephemeris_source`	`EphemerisSource`	Source for the body's position. Defaults to `EphemerisSource.DE440s`.	`None`
`gravity`	`GravityConfiguration`	Gravity model for this perturber. Defaults to point-mass.	`None`

Attributes:

Name	Type	Description
`body`	`ThirdBody`	The perturbing body
`ephemeris_source`	`EphemerisSource`	Ephemeris source
`gravity`	`GravityConfiguration`	Gravity model for this perturber

Example

import brahe as bh

# Point-mass Moon from DE440s
moon = bh.ThirdBodyConfiguration(bh.ThirdBody.MOON)

# Earth as an 8x8 spherical-harmonic perturber (for an EMB-centered
# propagation)
earth = bh.ThirdBodyConfiguration(
    bh.ThirdBody.EARTH,
    gravity=bh.GravityConfiguration.spherical_harmonic(degree=8, order=8),
)

Initialize instance.

body `property` ¶

body: Any

Get the perturbing body.

ephemeris_source `property` ¶

ephemeris_source: Any

Get the ephemeris source.

gravity `property` ¶

gravity: Any

Get the gravity model for this perturber.

TidesConfiguration ¶

TidesConfiguration(permanent: PermanentTideConfig, solid: SolidTideConfig = None, ocean: OceanTideConfig = None, ephemeris_source: EphemerisSource = Ellipsis)

Tidal correction configuration for ForceModelConfig.

Parameters:

Name	Type	Description	Default
`permanent`	`PermanentTideConfig`	Permanent-tide / tide-system handling.	required
`solid`	`SolidTideConfig`	Solid Earth tide configuration. None disables solid tides. Default is None.	`None`
`ocean`	`OceanTideConfig`	Ocean tide configuration. None disables ocean tides. Default is None.	`None`
`ephemeris_source`	`EphemerisSource`	Source for the Sun and Moon positions the tidal corrections are computed from. Defaults to EphemerisSource.LowPrecision (the analytic geocentric ephemerides), which is accurate enough for the ~1e-7 m/s^2 tidal perturbation. Set to a high-precision source to share positions with a third-body perturbation configured against the same source.	`Ellipsis`

Example

import brahe as bh

solid = bh.SolidTideConfig(frequency_dependent=True)
tides = bh.TidesConfiguration(permanent=bh.PermanentTideConfig.AUTO, solid=solid)

Initialize instance.

ephemeris_source `property` ¶

ephemeris_source: Any

Get the ephemeris source for the tidal Sun and Moon positions.

ocean `property` ¶

ocean: Any

Get the ocean tide configuration (None if disabled).

permanent `property` ¶

permanent: Any

Get the permanent tide configuration.

solid `property` ¶

solid: Any

Get the solid Earth tide configuration (None if disabled).

SolidTideConfig ¶

SolidTideConfig(frequency_dependent: bool = False, pole_tide: bool = False)

Solid Earth tide settings.

Controls whether Step 2 (frequency-dependent) IERS corrections are applied, and whether the solid Earth pole tide is applied.

Parameters:

Name	Type	Description	Default
`frequency_dependent`	`bool`	Apply IERS Step 2 frequency-dependent corrections. Default is False.	`False`
`pole_tide`	`bool`	Apply the solid Earth pole tide ΔC̄21/ΔS̄21 (IERS TN36 Section 6.4). Requires EOP initialization. Default is False.	`False`

Example

import brahe as bh

solid = bh.SolidTideConfig(frequency_dependent=True, pole_tide=True)
assert solid.frequency_dependent is True
assert solid.pole_tide is True

Initialize instance.

frequency_dependent `property` ¶

frequency_dependent: Any

Whether Step 2 frequency-dependent corrections are enabled.

pole_tide `property` ¶

pole_tide: Any

Whether the solid Earth pole tide is enabled.

OceanTideConfig ¶

OceanTideConfig(degree: int = 20, order: int = 20, include_admittance: bool = True, pole_tide: bool = False)

FES2004 ocean tide configuration (IERS TN36 Section 6.3) plus the ocean pole tide (Section 6.5).

Requires a one-time download of the IERS FES2004 coefficient file into the brahe cache on first use.

Parameters:

Name	Type	Description	Default
`degree`	`int`	Truncation degree, 2-100. Defaults to 20.	`20`
`order`	`int`	Truncation order, <= degree. Defaults to 20.	`20`
`include_admittance`	`bool`	Add secondary waves by admittance interpolation (TN36 Table 6.7). Defaults to True.	`True`
`pole_tide`	`bool`	Apply the ocean pole tide (2,1) term (TN36 Eq. 6.24). Requires EOP initialization. Defaults to False.	`False`

Example

import brahe as bh

ocean = bh.OceanTideConfig(degree=30, order=30)
tides = bh.TidesConfiguration(
    permanent=bh.PermanentTideConfig.AUTO,
    solid=bh.SolidTideConfig(frequency_dependent=True, pole_tide=True),
    ocean=ocean,
)

Initialize instance.

degree `property` ¶

degree: Any

Truncation degree of the ocean tide expansion.

include_admittance `property` ¶

include_admittance: Any

Whether secondary waves are added by admittance interpolation.

order `property` ¶

order: Any

Truncation order of the ocean tide expansion.

pole_tide `property` ¶

pole_tide: Any

Whether the ocean pole tide is enabled.

PermanentTideConfig ¶

PermanentTideConfig()

Permanent (zero-frequency) tide handling for the static gravity field.

Controls how the loaded model's C̄20 is reconciled with the solid-tide model.

Use the class attributes AUTO and OFF for the unit variants, or PermanentTideConfig.convert_to(system) to force a specific tide system.

Example

import brahe as bh

# Auto-detect from model flag (default)
perm = bh.PermanentTideConfig.AUTO

# Disable permanent-tide correction
perm = bh.PermanentTideConfig.OFF

# Force convert to a specific system
perm = bh.PermanentTideConfig.convert_to(bh.GravityModelTideSystem.ZeroTide)

Initialize instance.

AUTO `class-attribute` ¶

AUTO: Any = PermanentTideConfig.AUTO

Permanent (zero-frequency) tide handling for the static gravity field.

Controls how the loaded model's C̄20 is reconciled with the solid-tide model.

Use the class attributes AUTO and OFF for the unit variants, or PermanentTideConfig.convert_to(system) to force a specific tide system.

Example

import brahe as bh

# Auto-detect from model flag (default)
perm = bh.PermanentTideConfig.AUTO

# Disable permanent-tide correction
perm = bh.PermanentTideConfig.OFF

# Force convert to a specific system
perm = bh.PermanentTideConfig.convert_to(bh.GravityModelTideSystem.ZeroTide)

OFF `class-attribute` ¶

OFF: Any = PermanentTideConfig.OFF

Permanent (zero-frequency) tide handling for the static gravity field.

Controls how the loaded model's C̄20 is reconciled with the solid-tide model.

Use the class attributes AUTO and OFF for the unit variants, or PermanentTideConfig.convert_to(system) to force a specific tide system.

Example

import brahe as bh

# Auto-detect from model flag (default)
perm = bh.PermanentTideConfig.AUTO

# Disable permanent-tide correction
perm = bh.PermanentTideConfig.OFF

# Force convert to a specific system
perm = bh.PermanentTideConfig.convert_to(bh.GravityModelTideSystem.ZeroTide)

convert_to `staticmethod` ¶

convert_to(system: GravityModelTideSystem) -> PermanentTideConfig

Force the gravity field into the given tide system.

Parameters:

Name	Type	Description	Default
`system`	`GravityModelTideSystem`	Target tide system.	required

Returns:

Name	Type	Description
`PermanentTideConfig`	`PermanentTideConfig`	A PermanentTideConfig that converts to the given system.

Enumerations¶

AtmosphericModel ¶

AtmosphericModel()

Atmospheric density model selection.

Example

import brahe as bh

model = bh.AtmosphericModel.HARRIS_PRIESTER
model = bh.AtmosphericModel.NRLMSISE00

Initialize instance.

HARRIS_PRIESTER `class-attribute` ¶

HARRIS_PRIESTER: Any = AtmosphericModel(HarrisPriester)

Atmospheric density model selection.

Example

import brahe as bh

model = bh.AtmosphericModel.HARRIS_PRIESTER
model = bh.AtmosphericModel.NRLMSISE00

NRLMSISE00 `class-attribute` ¶

NRLMSISE00: Any = AtmosphericModel(NRLMSISE00)

Atmospheric density model selection.

Example

import brahe as bh

model = bh.AtmosphericModel.HARRIS_PRIESTER
model = bh.AtmosphericModel.NRLMSISE00

exponential `builtin` ¶

exponential(scale_height: float, rho0: float, h0: float) -> AtmosphericModel

Create exponential atmosphere model with custom parameters.

Parameters:

Name	Type	Description	Default
`scale_height`	`float`	Scale height in meters.	required
`rho0`	`float`	Reference density in kg/m³.	required
`h0`	`float`	Reference altitude in meters.	required

EclipseModel ¶

EclipseModel()

Eclipse model for solar radiation pressure calculations.

Example

import brahe as bh

eclipse = bh.EclipseModel.CONICAL
eclipse = bh.EclipseModel.CYLINDRICAL

Initialize instance.

CONICAL `class-attribute` ¶

CONICAL: Any = EclipseModel.Conical

Eclipse model for solar radiation pressure calculations.

Example

import brahe as bh

eclipse = bh.EclipseModel.CONICAL
eclipse = bh.EclipseModel.CYLINDRICAL

CYLINDRICAL `class-attribute` ¶

CYLINDRICAL: Any = EclipseModel.Cylindrical

Eclipse model for solar radiation pressure calculations.

Example

import brahe as bh

eclipse = bh.EclipseModel.CONICAL
eclipse = bh.EclipseModel.CYLINDRICAL

NONE `class-attribute` ¶

NONE: Any = EclipseModel.None

Eclipse model for solar radiation pressure calculations.

Example

import brahe as bh

eclipse = bh.EclipseModel.CONICAL
eclipse = bh.EclipseModel.CYLINDRICAL

ThirdBody ¶

ThirdBody()

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

Initialize instance.

DEIMOS `class-attribute` ¶

DEIMOS: Any = ThirdBody.Deimos

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

EARTH `class-attribute` ¶

EARTH: Any = ThirdBody.Earth

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

JUPITER `class-attribute` ¶

JUPITER: Any = ThirdBody.Jupiter

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

JUPITER_BARYCENTER `class-attribute` ¶

JUPITER_BARYCENTER: Any = ThirdBody.JupiterBarycenter

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

MARS `class-attribute` ¶

MARS: Any = ThirdBody.Mars

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

MARS_BARYCENTER `class-attribute` ¶

MARS_BARYCENTER: Any = ThirdBody.MarsBarycenter

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

MERCURY `class-attribute` ¶

MERCURY: Any = ThirdBody.Mercury

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

MOON `class-attribute` ¶

MOON: Any = ThirdBody.Moon

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

NEPTUNE `class-attribute` ¶

NEPTUNE: Any = ThirdBody.Neptune

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

NEPTUNE_BARYCENTER `class-attribute` ¶

NEPTUNE_BARYCENTER: Any = ThirdBody.NeptuneBarycenter

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

PHOBOS `class-attribute` ¶

PHOBOS: Any = ThirdBody.Phobos

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

SATURN `class-attribute` ¶

SATURN: Any = ThirdBody.Saturn

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

SATURN_BARYCENTER `class-attribute` ¶

SATURN_BARYCENTER: Any = ThirdBody.SaturnBarycenter

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

SUN `class-attribute` ¶

SUN: Any = ThirdBody.Sun

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

URANUS `class-attribute` ¶

URANUS: Any = ThirdBody.Uranus

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

URANUS_BARYCENTER `class-attribute` ¶

URANUS_BARYCENTER: Any = ThirdBody.UranusBarycenter

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

VENUS `class-attribute` ¶

VENUS: Any = ThirdBody.Venus

Third-body perturber.

Celestial bodies that can act as gravitational perturbers.

Example

import brahe as bh

sun = bh.ThirdBody.SUN
moon = bh.ThirdBody.MOON
ceres = bh.ThirdBody.Custom(name="Ceres", naif_id=2000001, gm=6.26325e10)

Custom `staticmethod` ¶

Custom(name: str, naif_id: int, gm: float) -> ThirdBody

Construct a user-defined perturbing body.

Parameters:

Name	Type	Description	Default
`name`	`str`	Human-readable name (e.g. `"Ceres"`).	required
`naif_id`	`int`	NAIF ID of the body.	required
`gm`	`float`	Gravitational parameter. Units: (m^3/s^2)	required

Returns:

Name	Type	Description
`ThirdBody`	`ThirdBody`	A user-defined perturbing body.

as_central_body `method descriptor` ¶

as_central_body() -> CentralBody

The CentralBody equivalent of this perturber, if it is a physical body brahe knows how to treat as a frame/parameter center.

Returns:

Type	Description
`CentralBody`	CentralBody \| None: Central-body equivalent, or None for the barycenter variants and Custom bodies.

body_fixed_frame `method descriptor` ¶

body_fixed_frame() -> ReferenceFrame

The body-fixed reference frame a gravity field attached to this body is expressed in (e.g. ITRF for Earth, LFPA for the Moon, MCMF for Mars).

Returns:

Type	Description
`ReferenceFrame`	ReferenceFrame \| None: Body-fixed frame, or None for the barycenter variants, Custom bodies, and bodies without a rotation model.

gm `method descriptor` ¶

gm() -> float

Gravitational parameter of the perturbing body.

Returns:

Name	Type	Description
`float`	`float`	Gravitational parameter. Units: (m^3/s^2)

naif_id `method descriptor` ¶

naif_id() -> int

NAIF ID of the perturbing body.

Returns:

Name	Type	Description
`int`	`int`	NAIF ID.

OccultingBody ¶

OccultingBody()

Occulting body for eclipse/shadow modeling in solar radiation pressure calculations.

Identifies a celestial body whose shadow may occult the sun as seen from the spacecraft.

Example

import brahe as bh

earth = bh.OccultingBody.Earth
custom = bh.OccultingBody.Custom(name="Europa", naif_id=502, radius=1560.8e3)

Initialize instance.

Earth `class-attribute` ¶

Earth: Any = OccultingBody.Earth

Occulting body for eclipse/shadow modeling in solar radiation pressure calculations.

Identifies a celestial body whose shadow may occult the sun as seen from the spacecraft.

Example

import brahe as bh

earth = bh.OccultingBody.Earth
custom = bh.OccultingBody.Custom(name="Europa", naif_id=502, radius=1560.8e3)

Mars `class-attribute` ¶

Mars: Any = OccultingBody.Mars

Occulting body for eclipse/shadow modeling in solar radiation pressure calculations.

Identifies a celestial body whose shadow may occult the sun as seen from the spacecraft.

Example

import brahe as bh

earth = bh.OccultingBody.Earth
custom = bh.OccultingBody.Custom(name="Europa", naif_id=502, radius=1560.8e3)

Moon `class-attribute` ¶

Moon: Any = OccultingBody.Moon

Occulting body for eclipse/shadow modeling in solar radiation pressure calculations.

Identifies a celestial body whose shadow may occult the sun as seen from the spacecraft.

Example

import brahe as bh

earth = bh.OccultingBody.Earth
custom = bh.OccultingBody.Custom(name="Europa", naif_id=502, radius=1560.8e3)

Custom `staticmethod` ¶

Custom(name: str, naif_id: int, radius: float) -> OccultingBody

Construct a user-defined occulting body.

Parameters:

Name	Type	Description	Default
`name`	`str`	Descriptive name of the body.	required
`naif_id`	`int`	NAIF ID of the physical body.	required
`radius`	`float`	Mean physical radius of the body. Units: (m)	required

Returns:

Name	Type	Description
`OccultingBody`	`OccultingBody`	A user-defined occulting body.

naif_id `method descriptor` ¶

naif_id() -> int

NAIF ID of the physical occulting body.

Returns:

Name	Type	Description
`int`	`int`	NAIF integer ID of the physical body.

naif_position_id `method descriptor` ¶

naif_position_id() -> int

NAIF ID to use when resolving the occulting body's position via SPK ephemerides.

Returns:

Name	Type	Description
`int`	`int`	NAIF integer ID to use for SPK position queries. Identical to `naif_id`
	`int`	for every variant (the physical body center).

radius `method descriptor` ¶

radius() -> float

Mean physical radius of the occulting body.

Returns:

Name	Type	Description
`float`	`float`	Physical radius of the body. Units: (m)

ParameterSource ¶

ParameterSource()

Source for a parameter value (fixed or from parameter vector).

Allows specifying whether a parameter comes from a fixed value or from an index in the parameter vector.

Example

import brahe as bh

# Fixed drag coefficient
cd = bh.ParameterSource.value(2.2)

# Variable mass from parameter vector index 0
mass = bh.ParameterSource.parameter_index(0)

Initialize instance.

get_index `method descriptor` ¶

get_index() -> int

Get the parameter index (if this is a ParameterIndex source).

Returns:

Type	Description
`int`	int or None: The parameter index, or None if this is a Value.

get_value `method descriptor` ¶

get_value() -> float

Get the fixed value (if this is a Value source).

Returns:

Type	Description
`float`	float or None: The fixed value, or None if this is a ParameterIndex.

is_parameter_index `method descriptor` ¶

is_parameter_index() -> Any

Check if this source references a parameter index.

is_value `method descriptor` ¶

is_value() -> Any

Check if this source is a fixed value.

parameter_index `builtin` ¶

parameter_index(index: int) -> ParameterSource

Create a parameter index source.

Parameters:

Name	Type	Description	Default
`index`	`int`	Index into the parameter vector.	required

Returns:

Name	Type	Description
`ParameterSource`	`ParameterSource`	A parameter source referencing a parameter vector index.

value `builtin` ¶

value(value: float) -> ParameterSource

Create a fixed value parameter source.

Parameters:

Name	Type	Description	Default
`value`	`float`	The fixed parameter value.	required

Returns:

Name	Type	Description
`ParameterSource`	`ParameterSource`	A parameter source with a fixed value.

Force Model Configuration¶

ForceModelConfig¶

ForceModelConfig ¶

central_body property ¶

drag property ¶

frame_transform property ¶

gravity property ¶

mass property ¶

relativity property ¶

srp property ¶

third_body property ¶

tides property ¶

cislunar_default builtin ¶

conservative_forces builtin ¶

default builtin ¶

earth_gravity builtin ¶

for_body builtin ¶

geo_default builtin ¶

high_fidelity builtin ¶

leo_default builtin ¶

lunar_default builtin ¶

mars_default builtin ¶

requires_params method descriptor ¶

two_body builtin ¶

validate method descriptor ¶

Central Body¶

CentralBody ¶

EMB class-attribute ¶

Earth class-attribute ¶

Mars class-attribute ¶

Moon class-attribute ¶

SSB class-attribute ¶

Custom staticmethod ¶

fixed_frame method descriptor ¶

from_naif_id staticmethod ¶

gm method descriptor ¶

inertial_frame method descriptor ¶

is_barycenter method descriptor ¶

naif_id method descriptor ¶

omega_vector method descriptor ¶

radius method descriptor ¶

Configuration Components¶

GravityConfiguration ¶

earth_zonal builtin ¶

get_degree method descriptor ¶

get_earth_zonal_degree method descriptor ¶

get_order method descriptor ¶

get_parallel method descriptor ¶

is_earth_zonal method descriptor ¶

is_point_mass method descriptor ¶

is_spherical_harmonic method descriptor ¶

point_mass builtin ¶

spherical_harmonic builtin ¶

zero builtin ¶

DragConfiguration ¶

area property ¶

body property ¶

cd property ¶

model property ¶

SolarRadiationPressureConfiguration ¶

area property ¶

cr property ¶

eclipse_model property ¶

occulting_bodies property ¶

ThirdBodyConfiguration ¶

body property ¶

ephemeris_source property ¶

gravity property ¶

TidesConfiguration ¶

ephemeris_source property ¶

ocean property ¶

permanent property ¶

solid property ¶

SolidTideConfig ¶

frequency_dependent property ¶

pole_tide property ¶

OceanTideConfig ¶

degree property ¶

include_admittance property ¶

order property ¶

central_body `property` ¶

drag `property` ¶

frame_transform `property` ¶

gravity `property` ¶

mass `property` ¶

relativity `property` ¶

srp `property` ¶

third_body `property` ¶

tides `property` ¶

cislunar_default `builtin` ¶

conservative_forces `builtin` ¶

default `builtin` ¶

earth_gravity `builtin` ¶

for_body `builtin` ¶

geo_default `builtin` ¶

high_fidelity `builtin` ¶

leo_default `builtin` ¶

lunar_default `builtin` ¶

mars_default `builtin` ¶

requires_params `method descriptor` ¶

two_body `builtin` ¶

validate `method descriptor` ¶

EMB `class-attribute` ¶

Earth `class-attribute` ¶

Mars `class-attribute` ¶

Moon `class-attribute` ¶

SSB `class-attribute` ¶

Custom `staticmethod` ¶

fixed_frame `method descriptor` ¶

from_naif_id `staticmethod` ¶

gm `method descriptor` ¶

inertial_frame `method descriptor` ¶

is_barycenter `method descriptor` ¶

naif_id `method descriptor` ¶

omega_vector `method descriptor` ¶

radius `method descriptor` ¶

earth_zonal `builtin` ¶

get_degree `method descriptor` ¶

get_earth_zonal_degree `method descriptor` ¶

get_order `method descriptor` ¶

get_parallel `method descriptor` ¶

is_earth_zonal `method descriptor` ¶

is_point_mass `method descriptor` ¶

is_spherical_harmonic `method descriptor` ¶

point_mass `builtin` ¶

spherical_harmonic `builtin` ¶

zero `builtin` ¶

area `property` ¶

body `property` ¶

cd `property` ¶

model `property` ¶

area `property` ¶

cr `property` ¶

eclipse_model `property` ¶

occulting_bodies `property` ¶

body `property` ¶

ephemeris_source `property` ¶

gravity `property` ¶

ephemeris_source `property` ¶

ocean `property` ¶

permanent `property` ¶

solid `property` ¶

frequency_dependent `property` ¶

pole_tide `property` ¶

degree `property` ¶

include_admittance `property` ¶

order `property` ¶

pole_tide `property` ¶

AUTO `class-attribute` ¶

OFF `class-attribute` ¶

convert_to `staticmethod` ¶

HARRIS_PRIESTER `class-attribute` ¶

NRLMSISE00 `class-attribute` ¶

exponential `builtin` ¶

CONICAL `class-attribute` ¶

CYLINDRICAL `class-attribute` ¶

NONE `class-attribute` ¶

DEIMOS `class-attribute` ¶

EARTH `class-attribute` ¶

JUPITER `class-attribute` ¶