30 lines
1.1 KiB
Python
30 lines
1.1 KiB
Python
"""JPL Planetary and Lunar Ephemeris DE406 for the jplephem package.
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This is the long-period ephemeris which is used by the Jet Propulsion
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Laboratory's online HORIZONS service for dates far in the past or
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future.
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:Name: DE406 (May 1997)
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:Years: -3000 through 3000
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:Planets: Yes
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:Sun/Moon: Yes
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:Nutations: No
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:Librations: No
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:Report: `Standish (1998) [PDF] <ftp://ssd.jpl.nasa.gov/pub/eph/planets/ioms/de405.iom.pdf>`_
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:Size: 190 MB
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This ephemeris is like `DE405 <http://pypi.python.org/pypi/de405>`_ but
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covers a longer time period. To keep its files from being too large,
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its size was reduced by permitting up to 1 meter of interpolation error
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for the position of the Moon, and 25 meters for all other solar system
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bodies. Since DE405 itself is often only accurate to within a few
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kilometers for planetary positions, the difference was not important for
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many users. You can get much higher accuracy from the more recent
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long-term ephemeris `DE422 <http://pypi.python.org/pypi/de422>`_ but at
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the cost of three times the RAM and disk space.
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To compute using this ephemeris in Python, see the `jplephem
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<http://pypi.python.org/pypi/jplephem>`_ package.
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"""
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