Observations

Module for the Observations class.

class jorbit.observation.Observations(observed_coordinates=None, times=None, observatories=None, astrometric_uncertainties=None, de_ephemeris_version='440', mpc_file=None)

Bases: object

The Observations class.

This is a container for astrometric observations of a particle at different times. When a user supplies times, coordinates, and observatory names, this class will under-the-hood pre-compute the required covariance matrices required for fitting, query Horizons to get the Barycentric positions of the observers, and store everything as ready-to-use-later JAX arrays.

Parameters:

• observed_coordinates (astropy.coordinates.sky_coordinate.SkyCoord | None)

• times (astropy.time.core.Time | None)

• observatories (str | list[str] | None)

• astrometric_uncertainties (astropy.units.quantity.Quantity | None)

• de_ephemeris_version (str | None)

• mpc_file (str | None)

property astrometric_uncertainties: jax.Array

Astrometric uncertainties of the observations in arcseconds.

property cov_log_dets: jax.Array

Log determinants of the covariance matrices.

property cov_matrices: jax.Array

Covariance matrices of the observations in arcsec^2.

property dec: jax.Array

Declination of the observations in radians, ICRS.

property inv_cov_matrices: jax.Array

Inverse covariance matrices of the observations in arcsec^-2.

property observatories: list[str] | str

Names of the observatories.

property observer_positions: jax.Array

Barycentric cartesian positions of the observers in AU.

property ra: jax.Array

Right ascension of the observations in radians, ICRS.

property times: jax.Array

Times of the observations in JD TDB.

property times_astropy: astropy.time.core.Time | None

Original astropy Time (TDB) if provided at construction; else None.