ssapy_toolkit.Coordinates.sky_angles

Functions

altitude2zenithangle(altitude[, deg])

Convert altitude to zenith angle.

gcrf_to_lat_lon(r, t)

Convert GCRF coordinates to latitude, longitude, and height above Earth's surface.

gcrf_to_radec(gcrf_coords)

Convert GCRF Cartesian coordinates to right ascension and declination.

gcrf_to_sim_geo(r_gcrf, t[, h])

Convert GCRF coordinates to simulated geodetic coordinates (latitude, longitude, height).

ra_dec([r, v, x, y, z, vx, vy, vz, r_earth, ...])

Compute the Right Ascension (RA) and Declination (Dec) of a position and velocity vector, relative to Earth's position and velocity.

sun_ra_dec(time_)

Calculate the Right Ascension and Declination of the Sun for a given time.

zenithangle2altitude(zenith_angle[, deg])

Convert zenith angle to altitude.

ssapy_toolkit.Coordinates.sky_angles.altitude2zenithangle(altitude: float, deg: bool = True) float[source]

Convert altitude to zenith angle.

Parameters: - altitude (float): The altitude of the object in degrees or radians. - deg (bool, optional): If True, the output is in degrees. If False, in radians. Default is True.

Returns: - float: Zenith angle in degrees or radians.

Author: Travis Yeager (yeager7@llnl.gov)

ssapy_toolkit.Coordinates.sky_angles.gcrf_to_lat_lon(r: ndarray, t: ndarray) ndarray[source]

Convert GCRF coordinates to latitude, longitude, and height above Earth’s surface.

Parameters: - r (np.ndarray): 3D position vector in GCRF coordinates (meters). - t (np.ndarray): Time array for conversion.

Returns: - Tuple of longitude, latitude, and height above the Earth’s surface.

ssapy_toolkit.Coordinates.sky_angles.gcrf_to_radec(gcrf_coords: ndarray) ndarray[source]

Convert GCRF Cartesian coordinates to right ascension and declination.

Parameters: - gcrf_coords (np.ndarray): 3D position vector in GCRF coordinates (x, y, z).

Returns: - Tuple of right ascension and declination in degrees.

ssapy_toolkit.Coordinates.sky_angles.gcrf_to_sim_geo(r_gcrf: ndarray, t: ndarray, h: float = 10) ndarray[source]

Convert GCRF coordinates to simulated geodetic coordinates (latitude, longitude, height).

Parameters: - r_gcrf (np.ndarray): 3D position vector in GCRF coordinates (meters). - t (np.ndarray): Time array for conversion. - h (float): Step size in seconds for time propagation.

Returns: - Simulated geodetic coordinates in meters.

ssapy_toolkit.Coordinates.sky_angles.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]

Compute the Right Ascension (RA) and Declination (Dec) of a position and velocity vector, relative to Earth’s position and velocity.

Parameters: - r (np.ndarray): Position vector of the object in 3D space. - v (np.ndarray): Velocity vector of the object. - x, y, z (float, optional): Individual Cartesian coordinates of the object. - vx, vy, vz (float, optional): Individual velocity components of the object. - r_earth (np.ndarray, optional): Earth’s position vector. Default is the origin. - v_earth (np.ndarray, optional): Earth’s velocity vector. Default is zero velocity. - input_unit (str, optional): The unit system used. Defaults to SI units.

Returns: - Tuple[np.ndarray, np.ndarray]: RA and Dec in radians.

ssapy_toolkit.Coordinates.sky_angles.sun_ra_dec(time_)[source]

Calculate the Right Ascension and Declination of the Sun for a given time.

Parameters: - time_ (Union[int, float, str]): The time for which to calculate the Sun’s position (in MJD or string format).

Returns: - Tuple[float, float]: Right Ascension and Declination of the Sun in radians.

ssapy_toolkit.Coordinates.sky_angles.zenithangle2altitude(zenith_angle: float, deg: bool = True) float[source]

Convert zenith angle to altitude.

Parameters: - zenith_angle (float): The zenith angle in degrees or radians. - deg (bool, optional): If True, the input is in degrees. If False, in radians. Default is True.

Returns: - float: Altitude in degrees or radians.

Author: Travis Yeager (yeager7@llnl.gov)