Add planetary reference frames like IAU_JUPITER

[brandon-rhodes]

Per the discussion brandon-rhodes/pyephem#48 over in the old PyEphem project, Skyfield should add support for planetary reference frames like IAU_JUPITER that express positions relative to the pole and equator of other planets.

[ghost]

http://astropedia.astrogeology.usgs.gov/download/Docs/WGCCRE/WGCCRE2009reprint.pdf may help, but there is presumably a later version.

[ghost]

See also:

http://astropedia.astrogeology.usgs.gov/download/Docs/WGCCRE/WGCCRE-Erratum-2011reprint.pdf

and

http://astrogeology.usgs.gov/groups/IAU-WGCCRE

It appears as though the IAU may now provide only limited updated data?

[brandon-rhodes]

Though it will be a few weeks before I can make progress on this issue, I want to go ahead and thank you, @barrycarter, for these links you are collecting—they will make it easier for this feature to go in sooner instead of later!

[ghost]

This is probably useless, but I enjoy cutting and pasting emails in issue-reporting forms:

Date: Wed, 13 Aug 2014 16:45:15 +0200
From: IAU Public [email protected]
To: Barry Carter [email protected]
Subject: Re: Latest update of WGCCRE2009.pdf?

Dear Barry Carter,

Thank you for your email. I have contacted the chair of the Working Group
mentioned to see if we can obtain a more recent report. Additionally their
website is below for further information:

http://astrogeology.usgs.gov/groups/IAU-WGCCRE

I will get in touch with you as soon as I have a response.

Best regards, Madeleine

/Madeleine Smith-Spanier /
/Database Manager/Assistant
_///_International Astronomical Union (IAU)//

UAI Secretariat 98-bis Blvd Arago, 75014 PARIS
Phone: +33 (0) 1 43 25 83 58
Fax: +33 (0) 1 43 25 26 16
Website: http://www.iau.org/

Le 07/08/2014 19:53, Barry Carter a écrit :

http://astropedia.astrogeology.usgs.gov/download/Docs/WGCCRE/WGCCRE2009rep
rint.pdf

is dated 23 October 2010 and states in part "Every three years the IAU
Working Group on Cartographic Coordinates and Rotational Elements revises
tables giving the directions of the poles of rotation and the prime
meridians of the planets, satellites, minor planets, and comets."

Where can I find the most recent version of this report, eg, the 2013
version?

[brandon-rhodes]

I have just been adding a new module to jplephem to read SPICE kernel files so that Skyfield can use them for the positions of, say, the Jovian moons. It looks like there are also kernel files for things like planetary orientations:

http://naif.jpl.nasa.gov/pub/naif/LADEE/kernels/pck/pck00010.tpc

So that might be one source of the data you want. I will comment here if I get time this year to add a reader for this file format to Skyfield!

[brandon-rhodes]

Closing this in favor of #417, which includes more recent discussion of how this will be implemented!