empyrean.get_observer_states

get_observer_states(obs_codes, epochs, frame=Frame.ICRF, origin=Origin(name='SSB'))[source]

Compute observer Cartesian states in a chosen frame and origin.

Cross product: N obs codes × M epochs = N*M observers.

Thin wrapper around Observers.from_codes() — prefer the classmethod when writing new code.

Parameters:

  • obs_codes (Sequence[str]) – MPC observatory codes (e.g. ["W84", "F51"]).

  • epochs (Epochs) – Observation epochs as an Epochs table, converted to TDB internally. Build one with Epochs.from_mjd(values, scale="tdb") (or scale="utc"); a bare array is refused, as it carries no time scale.

  • frame (Frame | str | int) – Reference frame for the returned states. Default Frame.ICRF.

  • origin (Origin | str | int) – Body the states are relative to. Default Origin.SSB.

Return type:

Observers

Notes

(Frame.ICRF, Origin.SSB) is the construction basis, required by ephemeris generation and orbit determination and returned untouched. See Observers.from_codes() for when another basis is the right request.

Return type:

Observers

Returns:

Observers – Observer states with obs_code, epoch, position, velocity, and observing_night.

Raises:

TypeError – epochs is not an Epochs table.

Parameters: