SPK API

Ephemeris(filepath, load_window=None)

SPK ephemeris container with cached merged body paths.

Parameters:

Name	Type	Description	Default
filepath	str or list[str]	One SPK kernel path or an ordered list of kernel paths.	required
load_window	tuple[TDBView, TDBView] or None	Inclusive scalar TDB window used when loading SPK segments. If omitted, all segments remain eligible for later path loads.	None

Initialize an ephemeris container from one SPK kernel set.

Parameters:

Name	Type	Description	Default
filepath	str or list[str]	One SPK kernel path or an ordered list of kernel paths.	required
load_window	tuple[TDBView, TDBView] or None	Inclusive scalar TDB window used to discard SPK segments that are entirely outside the requested coverage interval.	None

available_bodies property

Return body names that appear in the loaded SPK graph.

load_body(target_name, center_name='SOLAR SYSTEM BARYCENTER')

Load the SPK path from one center body to one target body.

Parameters:

Name	Type	Description	Default
target_name	str	NAIF target body name.	required
center_name	str	NAIF center body name.	"SOLAR SYSTEM BARYCENTER"

Returns:

Type	Description
tuple[tuple[MergedSegment, ...], tuple[float, ...]]	Path segments and signs. A negative sign means that the stored segment is used in reverse.

load_tt_minus_tdb_kernel()

Load and cache the TT - TDB kernel segment.

Returns:

Type	Description
TTMinusTDBKernel	Kernel wrapper for the time offset.

Raises:

Type	Description
ValueError	If the loaded kernels do not contain a TT - TDB segment.

clear_default_ephemeris()

Clear the process-local default ephemeris.

load_default_ephemeris()

Return the process-local default ephemeris.

set_default_ephemeris(ephemeris, *, load_window=None)

Register one process-local default ephemeris.

Parameters:

Name	Type	Description	Default
ephemeris	Ephemeris or str or sequence[str]	Default ephemeris source. This may be an already constructed :class:Ephemeris object, one kernel path, or a sequence of kernel paths.	required
load_window	tuple[TDBView, TDBView]	Inclusive scalar TDB load window forwarded to :class:Ephemeris when ephemeris is a path or path sequence. This argument must be omitted when ephemeris is already an :class:Ephemeris object.	None

Returns:

Type	Description
Ephemeris	The registered default ephemeris object.

Raises:

Type	Description
ValueError	If load_window is provided together with an existing :class:Ephemeris object.