[AstroPy] AstroPy Digest, Vol 156, Issue 8

[Matthew Burger]

Thanks for these suggestions. I've used spicepy, but astropy.coordinates was easier (for planets) and didn't add any dependencies. I haven't looked at skyfield yet.

Matt    

    
    Message: 2
    Date: Tue, 10 Sep 2019 15:41:29 +0200
    From: Juan Luis Cano <juanlu001 at gmail.com>
    To: Astronomical Python mailing list <astropy at python.org>
    Subject: Re: [AstroPy] Solar System ephemerides in astropy.coordinates
    Message-ID:
    	<CAFmivUVK9i4ELn80L2zj8Gf+ub24Q3O8GRffiSci+DstYkxBdw at mail.gmail.com>
    Content-Type: text/plain; charset="utf-8"
    
    Hello Matt,
    
    The SPK segments are hardcoded (see links and comments in
    https://github.com/astropy/astropy/issues/6472) so, unless I'm mistaken, I
    don't think this is something that can be easily done in Astropy. I would
    be interested to see this happening though.
    
    As an alternative, you might be interested in checking SpiceyPy
    https://github.com/AndrewAnnex/SpiceyPy/ (installable with pip and
    conda-forge) and try to combine it with astropy.coordinates.
    
    Regards,
    
    On Tue, Sep 10, 2019 at 3:28 PM Matthew Burger <mburger at stsci.edu> wrote:
    
    > I?m trying to use astropy.coordinates.solar_system_ephemeris to calculate
    > the RA and Dec of other bodies besides planets. Is this possible? I know
    > which JPL SPICE kernels I want to use, but I can?t load them. If I specify
    > another kernel with a url (e.g.,
    > https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/jup310.bsp),
    > it downloads the file but can?t use it.
    >
    >
    >
    > I?m using astropy 3.2.1 with python 3.7.4.
    >
    >
    >
    > Thanks,
    >
    > Matt
    >
    >
    >
    > *************************************************************
    >
    > Matthew Burger
    >
    > Archive Scientist
    >
    > Data Processing & Archive Services (DPAS), Deputy Branch Manager
    >
    > Space Telescope Science Institute
    >
    > mburger at stsci.edu
    >
    > 410/338-6810
    >
    > *************************************************************
    >
    >
    >
    >
    > _______________________________________________
    > AstroPy mailing list
    > AstroPy at python.org
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    -- 
    Juan Luis Cano
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    Message: 3
    Date: Tue, 10 Sep 2019 14:22:09 +0000
    From: Andrew Williams <Andrew.Williams at curtin.edu.au>
    To: Astronomical Python mailing list <astropy at python.org>
    Subject: Re: [AstroPy] Solar System ephemerides in astropy.coordinates
    Message-ID: <013e6789-fca9-de5a-c79a-642e06b00030 at curtin.edu.au>
    Content-Type: text/plain; charset="utf-8"
    
    
    Hi Matt, I'd give skyfield (https://rhodesmill.org/skyfield/) a try - 
    it's a complete rewrite of pyephem by the original package maintainer. 
    It's very fast, uses the JPL ephemeris as well as parsing satellite 
    TLEs, and plays nicely with astropy objects (converting times and 
    coordinates to and from astropy Time and SkyCoord objects).
    
    Andrew
    
    On 2019-09-10 9:41 PM, Juan Luis Cano wrote:
    > Hello Matt,
    > 
    > The SPK segments are hardcoded (see links and comments in 
    > https://github.com/astropy/astropy/issues/6472) so, unless I'm mistaken, 
    > I don't think this is something that can be easily done in Astropy. I 
    > would be interested to see this happening though.
    > 
    > As an alternative, you might be interested in checking SpiceyPy 
    > https://github.com/AndrewAnnex/SpiceyPy/ (installable with pip and 
    > conda-forge) and try to combine it with astropy.coordinates.
    > 
    > Regards,
    > 
    > On Tue, Sep 10, 2019 at 3:28 PM Matthew Burger <mburger at stsci.edu 
    > <mailto:mburger at stsci.edu>> wrote:
    > 
    >     I?m trying to use astropy.coordinates.solar_system_ephemeris to
    >     calculate the RA and Dec of other bodies besides planets. Is this
    >     possible? I know which JPL SPICE kernels I want to use, but I can?t
    >     load them. If I specify another kernel with a url (e.g.,
    >     https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/jup310.bsp),
    >     it downloads the file but can?t use it.____
    > 
    >     __ __
    > 
    >     I?m using astropy 3.2.1 with python 3.7.4.____
    > 
    >     __ __
    > 
    >     Thanks,____
    > 
    >     Matt____
    > 
    >     __ __
    > 
    >     *************************************************************____
    > 
    >     Matthew Burger____
    > 
    >     Archive Scientist____
    > 
    >     Data Processing & Archive Services (DPAS), Deputy Branch Manager____
    > 
    >     Space Telescope Science Institute____
    > 
    >     mburger at stsci.edu <mailto:mburger at stsci.edu>____
    > 
    >     410/338-6810____
    > 
    >     *************************************************************____
    > 
    >     __ __
    > 
    >     __ __
    > 
    >     _______________________________________________
    >     AstroPy mailing list
    >     AstroPy at python.org <mailto:AstroPy at python.org>
    >     https://mail.python.org/mailman/listinfo/astropy
    > 
    > 
    > 
    > -- 
    > Juan Luis Cano
    > 
    > _______________________________________________
    > AstroPy mailing list
    > AstroPy at python.org
    > https://mail.python.org/mailman/listinfo/astropy
    > 
    
    
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