Trajectory¶

class heliopy.spice.Trajectory(target)

Bases: object

A generic class for the trajectory of a single body.

Objects are initially created using only the body. To perform the actual trajectory calculation run generate_positions(). The generated positions are then available via. the attributes times, x, y, and z.

Parameters: spacecraft (str) – Name of the target. The name must be present in the loaded kernels.

Notes

When an instance of this class is created, a leapseconds kernel and a planets kernel are both automatically loaded.

furnish

Attributes Summary

 generated True if positions have been generated, False otherwise. observing_body Observing body. r Magnitude of position vectors. target The body whose coordinates are being calculated. times The list of datetime at which positions were last sampled. x x coordinates of position. y y coordinates of position. z z coordinates of position.

Methods Summary

 change_units(unit) Convert the positions to different units. generate_positions(times, observing_body, frame) Generate positions from a spice kernel.

Attributes Documentation

generated

True if positions have been generated, False otherwise.

observing_body

Observing body. The position vectors are all specified relative to this body.

r

Magnitude of position vectors.

target

The body whose coordinates are being calculated.

times

The list of datetime at which positions were last sampled.

x

x coordinates of position.

y

y coordinates of position.

z

z coordinates of position.

Methods Documentation

change_units(unit)

Convert the positions to different units.

Parameters: unit (astropy.units.Quantity) – Must be a unit of length (e.g. km, m, AU).
generate_positions(times, observing_body, frame)

Generate positions from a spice kernel.

Parameters: times (iterable of datetime) – An iterable (e.g. a list) of datetime objects at which the positions are calculated. observing_body (str) – The observing body. Output position vectors are given relative to the position of this body. See https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html for a list of bodies. frame (str) – The coordinate system to return the positions in. See https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/frames.html for a list of frames.