Reference Frame Router¶

CelestialFrame and the generic rotation_frame_to_frame/position_frame_to_frame/state_frame_to_frame functions convert between any two supported reference frames, including generic NAIF-ID variants for bodies without a dedicated named frame.

Note

For conceptual explanations and the full frame/kernel-requirement tables, see Reference Frame Router in the Learn section. For central-body propagation defaults, see Cislunar and Lunar Propagation and Propagation Around Other Central Bodies.

CelestialFrame¶

CelestialFrame ¶

CelestialFrame()

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

Initialize instance.

ECEF `class-attribute` ¶

ECEF: Any = CelestialFrame.ITRF

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

ECI `class-attribute` ¶

ECI: Any = CelestialFrame.GCRF

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

EMBI `class-attribute` ¶

EMBI: Any = CelestialFrame.EMBI

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

EME2000 `class-attribute` ¶

EME2000: Any = CelestialFrame.EME2000

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

EMR `class-attribute` ¶

EMR: Any = CelestialFrame.EMR

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

GCRF `class-attribute` ¶

GCRF: Any = CelestialFrame.GCRF

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

GSE `class-attribute` ¶

GSE: Any = CelestialFrame.GSE

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

ITRF `class-attribute` ¶

ITRF: Any = CelestialFrame.ITRF

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

LCI `class-attribute` ¶

LCI: Any = CelestialFrame.LCI

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

LFME `class-attribute` ¶

LFME: Any = CelestialFrame.LFME

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

LFPA `class-attribute` ¶

LFPA: Any = CelestialFrame.LFPA

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

MCI `class-attribute` ¶

MCI: Any = CelestialFrame.MCI

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

MCMF `class-attribute` ¶

MCMF: Any = CelestialFrame.MCMF

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

MOD `class-attribute` ¶

MOD: Any = CelestialFrame.MOD

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

SER `class-attribute` ¶

SER: Any = CelestialFrame.SER

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

SSBI `class-attribute` ¶

SSBI: Any = CelestialFrame.SSBI

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

TOD `class-attribute` ¶

TOD: Any = CelestialFrame.TOD

A reference frame supported by the centralized frame router (rotation_frame_to_frame, position_frame_to_frame, state_frame_to_frame).

Includes every named frame defined elsewhere in this module (GCRF, ITRF, EME2000, the lunar frames LFPA/LFME, and the Mars frame MCMF, plus the corresponding inertial frames LCI/MCI), the Earth-Moon and Solar System barycentric inertial frames (EMBI, SSBI), and three generic constructors for bodies without a dedicated named frame: BodyCenteredICRF(naif_id), BodyFixedIAU(naif_id), and BodyFixedPCK(center, frame_id).

Frame centers (NAIF ID): GCRF/ITRF/EME2000 -> Earth (399); LCI/LFPA/LFME -> Moon (301); MCI/MCMF -> Mars (499); EMBI -> 3; SSBI -> 0; BodyCenteredICRF(id)/BodyFixedIAU(id) -> id; BodyFixedPCK -> its center.

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

axes `property` ¶

axes: FrameAxes

Orientation of this frame's axes, independent of its origin.

Returns:

Name	Type	Description
`FrameAxes`	`FrameAxes`	The frame's axes

center `property` ¶

center: FrameCenter

Body or barycenter at this frame's origin.

The semantic form of center_naif_id: a FrameCenter naming either a single body (catalogued or a self-assigned raw ID) or the GM-weighted barycenter of a two-body pair. It compares equal to a NAIFId or a plain integer with the same NAIF ID.

Returns:

Name	Type	Description
`FrameCenter`	`FrameCenter`	The frame's origin

center_naif_id `property` ¶

center_naif_id: int

NAIF ID of the body or barycenter at this frame's origin.

Returns:

Name	Type	Description
`int`	`int`	NAIF ID of the frame's origin

synodic_origin `property` ¶

synodic_origin: Optional[SynodicOrigin]

Origin choice of a synodic frame (Synodic, EMR, SER, GSE).

A centered frame carrying synodic axes has no origin choice: its center is stored directly, so this returns None while synodic_primary and synodic_secondary still report the pair.

Returns:

Type	Description
`Optional[SynodicOrigin]`	Optional[SynodicOrigin]: Origin choice, or `None` for non-synodic frames

synodic_primary `property` ¶

synodic_primary: Optional[int]

NAIF ID of the synodic primary (Synodic, EMR, SER, GSE, and a centered frame with synodic axes).

Returns:

Type	Description
`Optional[int]`	Optional[int]: NAIF ID of the primary body, or `None` for non-synodic frames

synodic_secondary `property` ¶

synodic_secondary: Optional[int]

NAIF ID of the synodic secondary (Synodic, EMR, SER, GSE, and a centered frame with synodic axes).

Returns:

Type	Description
`Optional[int]`	Optional[int]: NAIF ID of the secondary body, or `None` for non-synodic frames

BodyCenteredICRF `staticmethod` ¶

BodyCenteredICRF(naif_id: int) -> CelestialFrame

ICRF-aligned axes centered on the given NAIF ID.

Parameters:

Name	Type	Description	Default
`naif_id`	`int`	NAIF ID of the frame's center	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	ICRF-aligned frame centered on `naif_id`

BodyFixedCustom `staticmethod` ¶

BodyFixedCustom(center: int, key: int) -> CelestialFrame

Body-fixed frame evaluated from a user-registered rotation callback (see register_custom_frame), centered on center.

For a body without a catalogued NAIF ID, self-assign a unique negative center (mirroring NAIF's convention for non-catalogued objects): rotation-only queries never consult the center, and translations will raise unless an ephemeris covering that ID is loaded.

Center IDs at or below -1_000_000_000 are reserved for synthetic synodic barycenter centers (see Synodic); self-assigning one to a custom body is unlikely to collide with an actual synodic pair's encoded ID, but is not rejected, since real user-defined bodies and loaded kernels may legitimately need any negative ID.

Parameters:

Name	Type	Description	Default
`center`	`int`	NAIF ID of the frame's center (may be self-assigned negative)	required
`key`	`int`	Registry key the frame's callbacks were registered under	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	Custom body-fixed frame for `key`, centered on `center`

BodyFixedIAU `staticmethod` ¶

BodyFixedIAU(naif_id: int) -> CelestialFrame

IAU/WGCCRE body-fixed frame of the given NAIF ID, centered on that same NAIF ID.

Parameters:

Name	Type	Description	Default
`naif_id`	`int`	NAIF ID of the body (see `iau_rotation_model_ids` for the supported set)	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	IAU/WGCCRE body-fixed frame of `naif_id`

BodyFixedPCK `staticmethod` ¶

BodyFixedPCK(center: int, frame_id: int) -> CelestialFrame

Body-fixed frame evaluated from a loaded binary PCK's frame_id, centered on center.

Parameters:

Name	Type	Description	Default
`center`	`int`	NAIF ID of the frame's center	required
`frame_id`	`int`	NAIF binary PCK frame class ID (e.g. 31008 for `MOON_PA_DE440`)	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	Body-fixed frame for `frame_id`, centered on `center`

Centered `staticmethod` ¶

Centered(center: FrameCenter | NAIFId | int, axes: FrameAxes) -> CelestialFrame

Frame centered on center with the given axes.

Returns the named shorthand whenever the pair has one (so Centered(399, FrameAxes.EME2000) is CelestialFrame.EME2000 and Centered(301, FrameAxes.ICRF) is CelestialFrame.LCI), and a generic centered frame otherwise. CelestialFrame.Centered(f.center, f.axes) == f holds for every canonical frame value. Where a named frame and a generic frame describe the same pair, the named form is returned: CelestialFrame.Synodic(SynodicOrigin.Barycenter, 10, 399) round trips to CelestialFrame.SER and CelestialFrame.Synodic(SynodicOrigin.Primary, 399, 10) to CelestialFrame.GSE, and CelestialFrame.BodyCenteredICRF at 399, 301, 499, 3 or 0 round trips to CelestialFrame.GCRF, CelestialFrame.LCI, CelestialFrame.MCI, CelestialFrame.EMBI or CelestialFrame.SSBI.

The origin is canonicalized on FrameCenter.naif_id, so FrameCenter.Barycenter(primary, secondary) and the equivalent raw synthetic ID select the same named frame. When no named form exists, the origin is stored as given, so those two spellings produce distinct (but identically translating) frames.

FrameAxes.EMR, FrameAxes.SER and FrameAxes.GSE are the same orientations as their generic synodic pairs, so they are accepted at any center: Centered(3, FrameAxes.EMR) is CelestialFrame.EMR and Centered(399, FrameAxes.EMR) is the Earth-centered frame with those same axes.

Parameters:

Name	Type	Description	Default
`center`	`FrameCenter \| NAIFId \| int`	The frame's origin	required
`axes`	`FrameAxes`	Orientation of the frame's axes	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	The frame with that center and those axes

Raises:

Type	Description
`TypeError`	If `center` is not a `FrameCenter`, a `NAIFId`, or an integer

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.center_naif_id == 499

Synodic `staticmethod` ¶

Synodic(origin: SynodicOrigin, primary: int, secondary: int) -> CelestialFrame

Generic two-body synodic (rotating) frame: x̂ from primary toward secondary, ẑ along the secondary's orbital angular momentum relative to the primary, centered per origin. The named frames are specific configurations: EMR == Synodic(Barycenter, 399, 301), SER == Synodic(Barycenter, 10, 399), GSE == Synodic(Primary, 399, 10).

Any NAIF ID is accepted for primary and secondary. For a Barycenter origin, the pair is encoded into a synthetic negative center ID; this encoding is collision-free when both IDs are in 0..=999, and both bodies must have packaged GM constants. IDs outside 0..=999 still construct successfully but produce a different encoding that no longer maps back to a synthetic center — this surfaces as an SPK/GM lookup error at transform time rather than a silent collision.

Parameters:

Name	Type	Description	Default
`origin`	`SynodicOrigin`	Origin choice (primary, secondary, or barycenter)	required
`primary`	`int`	NAIF ID of the primary body	required
`secondary`	`int`	NAIF ID of the secondary body	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	Generic synodic frame for the pair

from_string `staticmethod` ¶

from_string(s: str) -> CelestialFrame

Parses a CelestialFrame from its string representation (named variants only, case-insensitive), plus the common aliases "ECI" (-> GCRF) and "ECEF" (-> ITRF).

Parameters:

Name	Type	Description	Default
`s`	`str`	String representation of the reference frame	required

Returns:

Name	Type	Description
`CelestialFrame`	`CelestialFrame`	Parsed reference frame

Raises:

Type	Description
`ValueError`	If `s` is not a recognized reference frame name

Example

import brahe as bh

assert bh.CelestialFrame.from_string("ECI") == bh.CelestialFrame.GCRF

FrameCenter¶

FrameCenter ¶

FrameCenter()

Origin of a celestial frame, independent of its axes.

FrameCenter.Body(naif_id) names a NAIF-catalogued body or system barycenter, or any raw integer ID such as a self-assigned negative center. FrameCenter.Barycenter(primary, secondary) names the GM-weighted barycenter of a two-body pair, the origin the synodic frames compute analytically rather than reading from an ephemeris; it is a different point from a catalogued system barycenter such as NAIFId.EARTH_MOON_BARYCENTER, which is a body.

naif_id is the identity the frame router uses: two centers with the same naif_id translate identically, and CelestialFrame.Centered canonicalizes on it. Equality against another FrameCenter, a NAIFId, or a plain integer likewise compares naif_id.

Example

import brahe as bh

assert bh.CelestialFrame.MCI.center == bh.NAIFId.MARS
assert bh.CelestialFrame.MCI.center.name == "MARS"
assert bh.CelestialFrame.SER.center.name == "BARYCENTER(SUN, EARTH)"

Initialize instance.

body `property` ¶

body: Any

The single body at this origin, when there is one.

Returns:

Type	Description
`Any`	NAIFId \| int \| None: The `NAIFId` member for a catalogued body, the plain integer for any other ID, or `None` for a two-body barycenter

naif_id `property` ¶

naif_id: int

NAIF ID of this origin.

Returns:

Name	Type	Description
`int`	`int`	NAIF ID of the origin, synthetic and negative for a two-body barycenter

name `property` ¶

name: str

Name of this origin.

Returns:

Name	Type	Description
`str`	`str`	NAIF body name (or the raw integer ID for an uncatalogued body), or `BARYCENTER(primary, secondary)` for a two-body barycenter

Barycenter `staticmethod` ¶

Barycenter(primary: int | NAIFId, secondary: int | NAIFId) -> FrameCenter

GM-weighted barycenter of a two-body pair, as used by the synodic frames.

Parameters:

Name	Type	Description	Default
`primary`	`int \| NAIFId`	NAIF ID of the primary body	required
`secondary`	`int \| NAIFId`	NAIF ID of the secondary body	required

Returns:

Name	Type	Description
`FrameCenter`	`FrameCenter`	The two-body barycentric origin

Body `staticmethod` ¶

Body(naif_id: int | NAIFId) -> FrameCenter

A NAIF-catalogued body or system barycenter, or any raw integer ID.

Parameters:

Name	Type	Description	Default
`naif_id`	`int \| NAIFId`	NAIF ID of the body or system barycenter	required

Returns:

Name	Type	Description
`FrameCenter`	`FrameCenter`	The body-centered origin

from_string `staticmethod` ¶

from_string(s: str) -> FrameCenter

Parses a NAIF body name, accepted alias, or integer ID string into a body-centered origin.

The BARYCENTER(primary, secondary) form name prints for a two-body barycenter is not parsed; build that with Barycenter.

Parameters:

Name	Type	Description	Default
`s`	`str`	A NAIF body name (e.g. "MARS BARYCENTER"), an accepted alias (e.g. "SSB"), or an integer NAIF ID string	required

Returns:

Name	Type	Description
`FrameCenter`	`FrameCenter`	Parsed origin

Raises:

Type	Description
`ValueError`	If `s` names no known body and is not a valid integer ID

Example

import brahe as bh

assert bh.FrameCenter.from_string("mars") == bh.NAIFId.MARS

FrameAxes¶

FrameAxes ¶

FrameAxes()

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

Initialize instance.

EME2000 `class-attribute` ¶

EME2000: Any = FrameAxes.EME2000

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

EMR `class-attribute` ¶

EMR: Any = FrameAxes.EMR

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

GSE `class-attribute` ¶

GSE: Any = FrameAxes.GSE

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

ICRF `class-attribute` ¶

ICRF: Any = FrameAxes.ICRF

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

ITRF `class-attribute` ¶

ITRF: Any = FrameAxes.ITRF

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

LunarME `class-attribute` ¶

LunarME: Any = FrameAxes.LunarME

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

LunarPA `class-attribute` ¶

LunarPA: Any = FrameAxes.LunarPA

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

MOD `class-attribute` ¶

MOD: Any = FrameAxes.MOD

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

MarsFixed `class-attribute` ¶

MarsFixed: Any = FrameAxes.MarsFixed

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

SER `class-attribute` ¶

SER: Any = FrameAxes.SER

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

TOD `class-attribute` ¶

TOD: Any = FrameAxes.TOD

Orientation of a celestial frame, independent of its origin.

A CelestialFrame is the pair of one FrameCenter value and one FrameAxes value; CelestialFrame.Centered(center, axes) builds that pair and CelestialFrame.center / CelestialFrame.axes read it back.

The argument-free orientations are class attributes (ICRF, EME2000, MOD, TOD, ITRF, LunarPA, LunarME, MarsFixed, EMR, SER, GSE); the parameterized ones are built with BodyFixedIAU(naif_id), BodyFixedPCK(frame_id), BodyFixedCustom(key) and Synodic(primary, secondary).

Rotating axes (ITRF, the body-fixed families, and the synodic families) carry transport-velocity terms that depend only on the axes' angular velocity, so they apply unchanged to a frame centered on a body other than the orientation's usual center.

Example

import brahe as bh

mars_eme2000 = bh.CelestialFrame.Centered(bh.NAIFId.MARS, bh.FrameAxes.EME2000)
assert mars_eme2000.axes == bh.FrameAxes.EME2000

BodyFixedCustom `staticmethod` ¶

BodyFixedCustom(key: int) -> FrameAxes

Body-fixed axes from a user-registered rotation callback (see register_custom_frame), keyed by its registry key.

Parameters:

Name	Type	Description	Default
`key`	`int`	Registry key the frame's callbacks were registered under	required

Returns:

Name	Type	Description
`FrameAxes`	`FrameAxes`	Custom body-fixed axes for `key`

BodyFixedIAU `staticmethod` ¶

BodyFixedIAU(naif_id: int) -> FrameAxes

IAU/WGCCRE body-fixed axes of the given NAIF ID.

Parameters:

Name	Type	Description	Default
`naif_id`	`int`	NAIF ID of the body (see `iau_rotation_model_ids` for the supported set)	required

Returns:

Name	Type	Description
`FrameAxes`	`FrameAxes`	IAU/WGCCRE body-fixed axes of `naif_id`

BodyFixedPCK `staticmethod` ¶

BodyFixedPCK(frame_id: int) -> FrameAxes

Body-fixed axes evaluated from a loaded binary PCK's frame class ID.

Parameters:

Name	Type	Description	Default
`frame_id`	`int`	NAIF binary PCK frame class ID (e.g. 31008 for `MOON_PA_DE440`)	required

Returns:

Name	Type	Description
`FrameAxes`	`FrameAxes`	Body-fixed axes for `frame_id`

Synodic `staticmethod` ¶

Synodic(primary: int, secondary: int) -> FrameAxes

Generic two-body synodic (rotating) axes: x̂ from primary toward secondary, ẑ along the secondary's orbital angular momentum relative to the primary.

EMR, SER and GSE name the same orientations as the pairs Synodic(399, 301), Synodic(10, 399) and Synodic(399, 10).

Parameters:

Name	Type	Description	Default
`primary`	`int`	NAIF ID of the primary body	required
`secondary`	`int`	NAIF ID of the secondary body	required

Returns:

Name	Type	Description
`FrameAxes`	`FrameAxes`	Synodic axes for the pair

from_string `staticmethod` ¶

from_string(s: str) -> FrameAxes

Parses FrameAxes from its string representation (the eleven argument-free names, case-insensitively).

The parameterized variants are not parseable from a string; construct them with BodyFixedIAU, BodyFixedPCK, BodyFixedCustom or Synodic.

Parameters:

Name	Type	Description	Default
`s`	`str`	String representation of the axes	required

Returns:

Name	Type	Description
`FrameAxes`	`FrameAxes`	Parsed axes

Raises:

Type	Description
`ValueError`	If `s` is not a recognized axes name

Example

import brahe as bh

assert bh.FrameAxes.from_string("tod") == bh.FrameAxes.TOD

Router Functions¶

rotation_frame_to_frame `builtin` ¶

rotation_frame_to_frame(from_frame: CelestialFrame | ReferenceFrame, to_frame: CelestialFrame | ReferenceFrame, epc: Union[Epoch, Sequence[Epoch]]) -> ndarray

Computes the rotation matrix transforming from_frame axes into to_frame axes at epc.

Purely an orientation query: does not depend on, and does not query, either frame's center. This does not mean SPK is never touched: EMR, SER, and GSE orientations are themselves derived from SPK state/acceleration (auto-loading de440s), so a query involving one of those frames still queries SPK.

from_frame/to_frame accept a CelestialFrame or a ReferenceFrame: a registered body/sensor frame, or a bound orbit-relative frame (e.g. ReferenceFrame.RTN("SC")), resolved by walking the frame registry.

Parameters:

Name	Type	Description	Default
`from_frame`	`CelestialFrame \| ReferenceFrame`	Source reference frame	required
`to_frame`	`CelestialFrame \| ReferenceFrame`	Target reference frame	required
`epc`	`Epoch or Sequence[Epoch]`	Epoch instant for computation of the transformation. A sequence evaluates one matrix per epoch.	required

Returns:

Type	Description
`ndarray`	numpy.ndarray: 3x3 rotation matrix transforming `from_frame` -> `to_frame`, shape `(3, 3)` for a single epoch or `(n, 3, 3)` for a sequence of `n` epochs.

Raises:

Type	Description
`RuntimeError`	If either frame's orientation cannot be evaluated at `epc`

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_frame_to_frame(bh.CelestialFrame.MCI, bh.CelestialFrame.MCMF, epc)

position_frame_to_frame `builtin` ¶

position_frame_to_frame(from_frame: CelestialFrame | ReferenceFrame, to_frame: CelestialFrame | ReferenceFrame, epc: Union[Epoch, Sequence[Epoch]], x: Union[ndarray, Sequence], axis: int = -1) -> ndarray

Transforms a Cartesian position from from_frame to to_frame at epc.

Same hub-and-spoke design as state_frame_to_frame, without the velocity transport terms. Same-center conversions skip the translation lookup, but EMR/SER/GSE orientation still queries SPK ephemerides (auto-loading de440s), so a same-center conversion involving one of those frames is not SPK-free.

from_frame/to_frame accept a CelestialFrame or a ReferenceFrame: a registered body/sensor frame, or a bound orbit-relative frame (e.g. ReferenceFrame.RTN("SC")), resolved by walking the frame registry. A non-celestial frame's origin is the origin of the object it is bound to.

Parameters:

Name	Type	Description	Default
`from_frame`	`CelestialFrame \| ReferenceFrame`	Source reference frame	required
`to_frame`	`CelestialFrame \| ReferenceFrame`	Target reference frame	required
`epc`	`Epoch or Sequence[Epoch]`	Epoch instant for computation of the transformation. A sequence evaluates one epoch per vector (or broadcasts a single vector across all epochs).	required
`x`	`ndarray or list`	Cartesian position in `from_frame` axes/center (m), shape `(3,)`, or a batch of vectors with the 3 components along `axis` (for example shape `(n, 3)`).	required
`axis`	`int`	The axis of `x` along which the 3 components of a single vector lie; the remaining axes enumerate the batch. For a batch of shape `(n, 3)` the components lie along the last axis, so the default `-1` applies; a `(3, n)` column layout uses `axis=0`.	`-1`

Returns:

Type	Description
`ndarray`	numpy.ndarray: Cartesian position in `to_frame` axes/center (m), shape `(3,)` for a single input, or the batch layout of `x` (shape `(n, 3)` for a single vector with a sequence of `n` epochs).

Raises:

Type	Description
`RuntimeError`	If either frame's orientation cannot be evaluated at `epc`, or if the two frames have different centers and no ephemeris path exists between them

Example

import brahe as bh

bh.initialize_eop()

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
x_gcrf = [bh.R_EARTH + 500e3, 0.0, 0.0]
x_itrf = bh.position_frame_to_frame(bh.CelestialFrame.GCRF, bh.CelestialFrame.ITRF, epc, x_gcrf)

state_frame_to_frame `builtin` ¶

state_frame_to_frame(from_frame: CelestialFrame | ReferenceFrame, to_frame: CelestialFrame | ReferenceFrame, epc: Union[Epoch, Sequence[Epoch]], x: Union[ndarray, Sequence], axis: int = -1) -> ndarray

Transforms a Cartesian state (position and velocity) from from_frame to to_frame at epc.

Uses a hub-and-spoke design: the state is first rotated from from_frame axes into ICRF axes (an exact orientation + velocity-transport transform, still centered on from_frame's origin), then re-centered onto to_frame's origin if the two frames have different centers, then rotated into to_frame axes. Same-center conversions (e.g. GCRF <-> ITRF) skip the re-centering step, so that step never touches SPK; EMR/SER/GSE orientation still queries SPK ephemerides (auto-loading de440s) even for a same-center conversion like GCRF <-> GSE.

from_frame/to_frame accept a CelestialFrame or a ReferenceFrame: a registered body/sensor frame, or a bound orbit-relative frame (e.g. ReferenceFrame.RTN("SC")), resolved by walking the frame registry. Every link in a non-celestial frame's orientation chain must supply an angular velocity, since the velocity transport term is otherwise undefined.

Parameters:

Name	Type	Description	Default
`from_frame`	`CelestialFrame \| ReferenceFrame`	Source reference frame	required
`to_frame`	`CelestialFrame \| ReferenceFrame`	Target reference frame	required
`epc`	`Epoch or Sequence[Epoch]`	Epoch instant for computation of the transformation. A sequence evaluates one epoch per vector (or broadcasts a single vector across all epochs).	required
`x`	`ndarray or list`	Cartesian state in `from_frame` axes/center `[position (m), velocity (m/s)]`, shape `(6,)`, or a batch of vectors with the 6 components along `axis` (for example shape `(n, 6)`).	required
`axis`	`int`	The axis of `x` along which the 6 components of a single vector lie; the remaining axes enumerate the batch. For a batch of shape `(n, 6)` the components lie along the last axis, so the default `-1` applies; a `(6, n)` column layout uses `axis=0`.	`-1`

Returns:

Type	Description
`ndarray`	numpy.ndarray: Cartesian state in `to_frame` axes/center `[position (m), velocity (m/s)]`, shape `(6,)` for a single input, or the batch layout of `x` (shape `(n, 6)` for a single vector with a sequence of `n` epochs).

Raises:

Type	Description
`RuntimeError`	If either frame's orientation cannot be evaluated at `epc`, or if the two frames have different centers and no ephemeris path exists between them

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
x_gcrf = [1e8, -2e8, 5e7, 1.0e3, -2.0e3, 0.5e3]
x_lfpa = bh.state_frame_to_frame(bh.CelestialFrame.GCRF, bh.CelestialFrame.LFPA, epc, x_gcrf)

Generic IAU/WGCCRE Body-Fixed Rotations¶

rotation_icrf_to_body_fixed_iau `builtin` ¶

rotation_icrf_to_body_fixed_iau(naif_id: int, epc: Union[Epoch, Sequence[Epoch]]) -> ndarray

Computes the rotation matrix from the ICRF to the IAU/WGCCRE body-fixed frame of naif_id at epc.

Parameters:

Name	Type	Description	Default
`naif_id`	`int`	NAIF ID of the body (see `iau_rotation_model_ids` for the supported set)	required
`epc`	`Epoch or Sequence[Epoch]`	Epoch instant for computation of the transformation matrix. A sequence evaluates one matrix per epoch.	required

Returns:

Type	Description
`ndarray`	numpy.ndarray: 3x3 rotation matrix transforming ICRF -> body-fixed, shape `(3, 3)` for a single epoch or `(n, 3, 3)` for a sequence of `n` epochs.

Raises:

Type	Description
`RuntimeError`	If no IAU/WGCCRE rotation model is embedded for `naif_id`

Example

import brahe as bh

epc = bh.Epoch.from_datetime(2024, 3, 1, 0, 0, 0.0, 0.0, bh.UTC)
r = bh.rotation_icrf_to_body_fixed_iau(499, epc)  # Mars

iau_rotation_model_ids `builtin` ¶

iau_rotation_model_ids() -> list[int]

Sorted list of NAIF IDs with an embedded IAU/WGCCRE rotation model.

Returns:

Type	Description
`list[int]`	list[int]: Sorted NAIF IDs supported by `rotation_icrf_to_body_fixed_iau`

Example

import brahe as bh

ids = bh.iau_rotation_model_ids()
assert 499 in ids  # Mars

Reference Frame Router¶

CelestialFrame¶

CelestialFrame ¶

ECEF class-attribute ¶

ECI class-attribute ¶

EMBI class-attribute ¶

EME2000 class-attribute ¶

EMR class-attribute ¶

GCRF class-attribute ¶

GSE class-attribute ¶

ITRF class-attribute ¶

LCI class-attribute ¶

LFME class-attribute ¶

LFPA class-attribute ¶

MCI class-attribute ¶

MCMF class-attribute ¶

MOD class-attribute ¶

SER class-attribute ¶

SSBI class-attribute ¶

TOD class-attribute ¶

axes property ¶

center property ¶

center_naif_id property ¶

synodic_origin property ¶

synodic_primary property ¶

synodic_secondary property ¶

BodyCenteredICRF staticmethod ¶

BodyFixedCustom staticmethod ¶

BodyFixedIAU staticmethod ¶

BodyFixedPCK staticmethod ¶

Centered staticmethod ¶

Synodic staticmethod ¶

from_string staticmethod ¶

FrameCenter¶

FrameCenter ¶

body property ¶

naif_id property ¶

name property ¶

Barycenter staticmethod ¶

Body staticmethod ¶

from_string staticmethod ¶

FrameAxes¶

FrameAxes ¶

EME2000 class-attribute ¶

EMR class-attribute ¶

GSE class-attribute ¶

ICRF class-attribute ¶

ITRF class-attribute ¶

LunarME class-attribute ¶

LunarPA class-attribute ¶

MOD class-attribute ¶

MarsFixed class-attribute ¶

SER class-attribute ¶

TOD class-attribute ¶

BodyFixedCustom staticmethod ¶

BodyFixedIAU staticmethod ¶

BodyFixedPCK staticmethod ¶

Synodic staticmethod ¶

from_string staticmethod ¶

Router Functions¶

rotation_frame_to_frame builtin ¶

position_frame_to_frame builtin ¶

state_frame_to_frame builtin ¶

Generic IAU/WGCCRE Body-Fixed Rotations¶

rotation_icrf_to_body_fixed_iau builtin ¶

iau_rotation_model_ids builtin ¶

See Also¶

ECEF `class-attribute` ¶

ECI `class-attribute` ¶

EMBI `class-attribute` ¶

EME2000 `class-attribute` ¶

EMR `class-attribute` ¶

GCRF `class-attribute` ¶

GSE `class-attribute` ¶

ITRF `class-attribute` ¶

LCI `class-attribute` ¶

LFME `class-attribute` ¶

LFPA `class-attribute` ¶

MCI `class-attribute` ¶

MCMF `class-attribute` ¶

MOD `class-attribute` ¶

SER `class-attribute` ¶

SSBI `class-attribute` ¶

TOD `class-attribute` ¶

axes `property` ¶

center `property` ¶

center_naif_id `property` ¶

synodic_origin `property` ¶

synodic_primary `property` ¶

synodic_secondary `property` ¶

BodyCenteredICRF `staticmethod` ¶

BodyFixedCustom `staticmethod` ¶

BodyFixedIAU `staticmethod` ¶

BodyFixedPCK `staticmethod` ¶

Centered `staticmethod` ¶

Synodic `staticmethod` ¶

from_string `staticmethod` ¶

body `property` ¶

naif_id `property` ¶

name `property` ¶

Barycenter `staticmethod` ¶

Body `staticmethod` ¶

from_string `staticmethod` ¶

EME2000 `class-attribute` ¶

EMR `class-attribute` ¶

GSE `class-attribute` ¶

ICRF `class-attribute` ¶

ITRF `class-attribute` ¶

LunarME `class-attribute` ¶

LunarPA `class-attribute` ¶

MOD `class-attribute` ¶

MarsFixed `class-attribute` ¶

SER `class-attribute` ¶

TOD `class-attribute` ¶

BodyFixedCustom `staticmethod` ¶

BodyFixedIAU `staticmethod` ¶

BodyFixedPCK `staticmethod` ¶

Synodic `staticmethod` ¶

from_string `staticmethod` ¶

rotation_frame_to_frame `builtin` ¶

position_frame_to_frame `builtin` ¶

state_frame_to_frame `builtin` ¶

rotation_icrf_to_body_fixed_iau `builtin` ¶

iau_rotation_model_ids `builtin` ¶