Reference Frames

Coordinate reference frames and ephemeris data.

Supported Frames

Abbreviation	Name	Description
ICRF	International Celestial Reference Frame	Inertial frame
ECLIPJ2000	Ecliptic J2000	Ecliptic plane at J2000
IAU_EARTH	IAU Earth	Earth body-fixed frame
ITRF	International Terrestrial Reference Frame	Earth-fixed

Quick Example

import lox_space as lox

# Create a frame
icrf = lox.Frame("ICRF")
itrf = lox.Frame("ITRF")

# Load ephemeris data
spk = lox.SPK("/path/to/de440.bsp")

# Transform states between frames
state_icrf = state.to_frame(itrf, provider=eop_provider)

# Transform between origins
state_moon = state.to_origin(lox.Origin("Moon"), spk)

Frame

Represents a reference frame for positioning and transformations.

Supported frames: - ICRF: International Celestial Reference Frame (inertial) - GCRF: Geocentric Celestial Reference Frame (inertial, Earth-centered) - CIRF: Celestial Intermediate Reference Frame - TIRF: Terrestrial Intermediate Reference Frame - ITRF: International Terrestrial Reference Frame (Earth-fixed) - Body-fixed frames: IAU_EARTH, IAU_MOON, IAU_MARS, etc.

Parameters:

abbreviation
–

Frame abbreviation (e.g., "ICRF", "ITRF", "IAU_MOON").

Raises:

ValueError –

If the frame abbreviation is not recognized.

Examples:

>>> icrf = lox.Frame("ICRF")
>>> itrf = lox.Frame("ITRF")

Methods:

abbreviation –

Return the abbreviation of this reference frame.
name –

Return the full name of this reference frame.

abbreviation

abbreviation() -> str

Return the abbreviation of this reference frame.

name

name() -> str

Return the full name of this reference frame.

SPK

SPICE SPK (Spacecraft and Planet Kernel) ephemeris data.

SPK files contain position and velocity data for celestial bodies and spacecraft. They are used for orbit propagation, frame transformations, and visibility analysis.