across.tools.ephemeris.tle_ephem

Classes

TLEEphemeris

TLE (Two-Line Element) based satellite ephemeris calculator.

Functions

compute_tle_ephemeris(begin, end, step_size, tle)

Compute the ephemeris for a space object using TLE data.

Module Contents

class TLEEphemeris(begin, end, step_size=60, tle=None)[source]

Bases: across.tools.ephemeris.base.Ephemeris

TLE (Two-Line Element) based satellite ephemeris calculator.

This class implements satellite position and velocity calculations using TLE data through the SGP4 propagator. It converts TEME (True Equator Mean Equinox) coordinates to ITRS (International Terrestrial Reference System) and GCRS (Geocentric Celestial Reference System). ITRS coordinates are stored as astropy EarthLocation objects, while GCRS coordinates are stored as astropy SkyCoord objects.

Parameters:

begin (Union[datetime, Time]) – Start time for ephemeris calculations
end (Union[datetime, Time]) – End time for ephemeris calculations
step_size (Union[int, TimeDelta, timedelta], optional) – Time step between calculations, defaults to 60 seconds
tle (Optional[TLE], optional) – TLE data object containing orbital elements, defaults to None

tle[source]

TLE data object used for calculations

Type:: Optional[TLE]

earth_location[source]

Satellite positions in ITRS coordinates

Type:: EarthLocation

gcrs[source]

Satellite positions in GCRS coordinates

Type:: SkyCoord

prepare_data()[source]

Calculates satellite ephemeris using TLE data and SGP4 propagator

Raises:: ValueError – If no TLE data is provided when preparing calculations

Notes

The calculation process involves: 1. Converting TLE to Satrec object 2. Calculating TEME positions using SGP4 3. Converting TEME to ITRS coordinates 4. Converting ITRS to GCRS coordinates

tle: across.tools.core.schemas.tle.TLE | None = None[source]

prepare_data()[source]

Calculate ephemeris based on TLE data

_calc()[source]

Calculate ephemeris data based on the coordinates computed by prepare_data(). Overloads the base class method to as rust-ephem already computes all necessary data during prepare_data().

compute_tle_ephemeris(begin, end, step_size, tle)[source]

Compute the ephemeris for a space object using TLE data.

Parameters:

begin (Union[datetime, Time]) – The start time for the ephemeris computation.
end (Union[datetime, Time]) – The end time for the ephemeris computation.
step_size (Union[int, timedelta, TimeDelta]) – Time step size between ephemeris points, in seconds if int
tle (TLE) – The TLE data entry for the space object.

Returns:

The computed ephemeris object containing the position and velocity data.

Return type:

Ephemeris