earth_orientation_table

class astropy.utils.iers.earth_orientation_table[source]

Bases: astropy.utils.state.ScienceState

Default IERS table for Earth rotation and reference systems service.

These tables are used to calculate the offsets between UT1 and UTC and for conversion to Earth-based coordinate systems.

The state itself is an IERS table, as an instance of one of the IERS classes. The default, the auto-updating IERS_Auto class, should suffice for most purposes.

Examples

To temporarily use the IERS-B file packaged with astropy:

>>> from astropy.utils import iers
>>> from astropy.time import Time
>>> iers_b = iers.IERS_B.open(iers.IERS_B_FILE)
>>> with iers.earth_orientation_table.set(iers_b):
...     print(Time('2000-01-01').ut1.isot)
2000-01-01T00:00:00.355

To use the most recent IERS-A file for the whole session:

>>> iers_a = iers.IERS_A.open(iers.IERS_A_URL)  
>>> iers.earth_orientation_table.set(iers_a)  
<ScienceState earth_orientation_table: <IERS_A length=17463>...>

To go back to the default (of IERS_Auto):

>>> iers.earth_orientation_table.set(None)  
<ScienceState earth_orientation_table: <IERS_Auto length=17428>...>

Methods Summary

validate(value) Validate the value and convert it to its native type, if necessary.

Methods Documentation

classmethod validate(value)[source]

Validate the value and convert it to its native type, if necessary.