CelestialCoordinates

class sofia_redux.scan.coordinate_systems.celestial_coordinates.CelestialCoordinates(coordinates=None, unit='degree', copy=True)

Bases: SphericalCoordinates

Initialize a CelestialCoordinates object.

Celestial coordinates are used to represent spherical coordinates on the sky with respect to a given pole. The functionality implemented here allows for transformations between spherical coordinates with differing poles or zero-longitude definitions.

Parameters:

coordinateslist or tuple or array-like or units.Quantity, optional

The coordinates used to populate the object during initialization. The first (0) value or index should represent longitudinal coordinates, and the second should represent latitude.

unitunits.Unit or str, optional

The angular unit for the spherical coordinates. The default is ‘degree’.

copybool, optional

Whether to explicitly perform a copy operation on the input coordinates when storing them into these coordinates. Note that it is extremely unlikely for the original coordinates to be passed in as a reference due to the significant checks performed on them.

Methods Summary

convert(from_coordinates, to_coordinates)	Convert one type of coordinates to another.
convert_from(coordinates)	Convert coordinates from another (or same) system to these coordinates.
convert_from_celestial(celestial)	Convert coordinates from another celestial frame onto this one.
convert_to(coordinates)	Convert coordinates to another system.
convert_to_celestial(celestial)	Convert these coordinates to another celestial system.
copy()	Return a copy of the celestial coordinates.
from_equatorial(equatorial)	Set the celestial coordinates from those given.
get_equatorial()	Return an equatorial representation of the celestial coordinates.
get_equatorial_class()	Return the equatorial class.
get_equatorial_pole()	Return the equatorial pole coordinates.
get_equatorial_position_angle()	Return the equatorial position angle of the celestial coordinates.
get_pole(inclination, rising_ra[, reference])	Get the pole from inclination and rising RA angles.
get_zero_longitude()	Return the zero longitude value.
get_zero_longitude_from(from_coordinates, ...)	Return the zero longitude of one coordinates system in another.
to_equatorial([equatorial])	Convert these celestial coordinates to equatorial coordinates.

Methods Documentation

convert(from_coordinates, to_coordinates)

Convert one type of coordinates to another.

The to_coordinates will be updated in-place.

Parameters:

from_coordinatesCelestialCoordinates

to_coordinatesCelestialCoordinates

Returns:

None

convert_from(coordinates)

Convert coordinates from another (or same) system to these coordinates.

Parameters:

coordinatesCelestialCoordinates or Coordinate2D

Returns:

None

convert_from_celestial(celestial)

Convert coordinates from another celestial frame onto this one.

Parameters:

celestialCelestialCoordinates

Returns:

None

convert_to(coordinates)

Convert coordinates to another system.

Parameters:

coordinatesCelestialCoordinates or Coordinate2D

Returns:

None

convert_to_celestial(celestial)

Convert these coordinates to another celestial system.

Parameters:

celestialCelestialCoordinates

Returns:

None

copy()

Return a copy of the celestial coordinates.

Returns:

CelestialCoordinates

from_equatorial(equatorial)

Set the celestial coordinates from those given.

Parameters:

equatorialEquatorialCoordinates

Returns:

None

get_equatorial()

Return an equatorial representation of the celestial coordinates.

Returns:

EquatorialCoordinates

classmethod get_equatorial_class()

Return the equatorial class.

Returns:

EquatorialCoordinates

abstract get_equatorial_pole()

Return the equatorial pole coordinates.

Returns:

EquatorialCoordinates

get_equatorial_position_angle()

Return the equatorial position angle of the celestial coordinates.

Returns:

astropy.units.Quantity

classmethod get_pole(inclination, rising_ra, reference=None)

Get the pole from inclination and rising RA angles.

Parameters:

inclinationastropy.units.Quantity

The inclination angle.

rising_raastropy.units.Quantity

The rising Right Ascension.

referenceCelestialCoordinates, optional

If supplied sets the coordinates in the reference system and converts it to equatorial coordinates.

Returns:

poleEquatorialCoordinates

abstract get_zero_longitude()

Return the zero longitude value.

Returns:

astropy.units.Quantity

classmethod get_zero_longitude_from(from_coordinates, to_coordinates)

Return the zero longitude of one coordinates system in another.

Parameters:

from_coordinatesEquatorialCoordinates

The coordinates from which to determine zero longitude.

to_coordinatesCelestialCoordinates

The coordinate system in which to return the zero longitude.

Returns:

zero_longitudeastropy.units.Quantity

The zero longitude angle.

to_equatorial(equatorial=None)

Convert these celestial coordinates to equatorial coordinates.

Parameters:

equatorialEquatorialCoordinates, optional

The equatorial coordinates that will hold these coordinates. If

Returns:

equatorialEquatorialCoordinates