PrecessedGeocentric¶
-
class
astropy.coordinates.
PrecessedGeocentric
(*args, **kwargs)[source] [edit on github]¶ Bases:
astropy.coordinates.BaseCoordinateFrame
A coordinate frame defined in a similar manner as GCRS, but precessed to a requested (mean) equinox. Note that this does not end up the same as regular GCRS even for J2000 equinox, because the GCRS orientation is fixed to that of ICRS, which is not quite the same as the dynamical J2000 orientation.
This frame has these frame attributes:
equinox
The (mean) equinox to precess the coordinates to.
obstime
The time at which the observation is taken. Used for determining the position of the Earth.
obsgeoloc
3-vector giving the position of the observer relative to the center-of-mass of the Earth, oriented the same as BCRS/ICRS. Defaults to 0, meaning “true” GCRS.
obsgeovel
3-vector giving the velocity of the observer relative to the center-of-mass of the Earth, oriented the same as BCRS/ICRS. Defaults to 0, meaning “true” GCRS.
Parameters: representation :
BaseRepresentation
or NoneA representation object or None to have no data (or use the other keywords)
ra :
Angle
, optional, must be keywordThe RA for this object (
dec
must also be given andrepresentation
must be None).dec :
Angle
, optional, must be keywordThe Declination for this object (
ra
must also be given andrepresentation
must be None).distance :
Quantity
, optional, must be keywordThe Distance for this object along the line-of-sight. (
representation
must be None).copy : bool, optional
If
True
(default), make copies of the input coordinate arrays. Can only be passed in as a keyword argument.Attributes Summary
default_representation
equinox
frame_attributes
frame_specific_representation_info
name
obsgeoloc
obsgeovel
obstime
Attributes Documentation
-
default_representation
¶
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equinox
= <Time object: scale='utc' format='jyear_str' value=J2000.000>¶
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frame_attributes
= OrderedDict([('equinox', <astropy.coordinates.baseframe.TimeFrameAttribute object at 0x7f2fca9ffb50>), ('obstime', <astropy.coordinates.baseframe.TimeFrameAttribute object at 0x7f2fca9ffb90>), ('obsgeoloc', <astropy.coordinates.baseframe.QuantityFrameAttribute object at 0x7f2fca9ffbd0>), ('obsgeovel', <astropy.coordinates.baseframe.QuantityFrameAttribute object at 0x7f2fca9ffc50>)])¶
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frame_specific_representation_info
¶
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name
= 'precessedgeocentric'¶
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obsgeoloc
= <Quantity [ 0., 0., 0.] m>¶
-
obsgeovel
= <Quantity [ 0., 0., 0.] m / s>¶
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obstime
= <Time object: scale='utc' format='jyear_str' value=J2000.000>¶