ssapy_toolkit.Compute.proper_motions

Functions

proper_motion(x, y, z, vx, vy, vz[, xe, ye, ...])

Calculate the proper motion of an object in space relative to Earth.

proper_motion_ra_dec([r, v, x, y, z, vx, ...])

Calculate the proper motion in right ascension (RA) and declination (DEC) for a given position and velocity in 3D space.

ssapy_toolkit.Compute.proper_motions.proper_motion(x: ndarray, y: ndarray, z: ndarray, vx: ndarray, vy: ndarray, vz: ndarray, xe: float = 0, ye: float = 0, ze: float = 0, vxe: float = 0, vye: float = 0, vze: float = 0, input_unit: str = 'si') float[source]

Calculate the proper motion of an object in space relative to Earth.

Parameters: x, y, z (np.ndarray): Position coordinates of the object. vx, vy, vz (np.ndarray): Velocity components of the object. xe, ye, ze (float): Position of Earth. vxe, vye, vze (float): Velocity of Earth. input_unit (str): The unit for proper motion (‘si’ or ‘rebound’).

Returns: float or None: The proper motion in arcseconds per year, or None if the object is at the Earth’s position.

Author: Travis Yeager (yaeger7@llnl.gov)

ssapy_toolkit.Compute.proper_motions.proper_motion_ra_dec(r: ndarray = None, v: ndarray = None, x: float = None, y: float = None, z: float = None, vx: float = None, vy: float = None, vz: float = None, r_earth: ndarray = array([0, 0, 0]), v_earth: ndarray = array([0, 0, 0]), input_unit: str = 'si') ndarray[source]

Calculate the proper motion in right ascension (RA) and declination (DEC) for a given position and velocity in 3D space.

Parameters: - r (np.ndarray): 3D position vector (x, y, z) in SI units (m). Default is None. - v (np.ndarray): 3D velocity vector (vx, vy, vz) in SI units (m/s). Default is None. - x, y, z (float): Individual coordinates for position (in meters). These are optional if r is provided. - vx, vy, vz (float): Individual velocities (in m/s). These are optional if v is provided. - r_earth (np.ndarray): 3D position vector of Earth (default is [0, 0, 0]). - v_earth (np.ndarray): 3D velocity vector of Earth (default is [0, 0, 0]). - input_unit (str): The units for the output. Options are ‘si’ (SI units) or ‘rebound’ (rebound units). Default is ‘si’.

Returns: - Tuple of proper motion in right ascension and declination (in arcseconds per second) if input_unit is ‘si’,

or in rebound units if input_unit is ‘rebound’.