<p>Be aware there are differing formats. SPK is the newer format - the older text format seems to be deprecated.</p>

<p>It's worth having a look at the documentation on <a href="https://pypi.python.org/pypi/jplephem" rel="nofollow noreferrer">this jplephem python library</a> as it explains the format reasonably well. If you do use SPK, you'll need to read all of <a href="https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/FORTRAN/req/spk.html" rel="nofollow noreferrer">the documentation in NASA's SPK repository</a></p>

<p>I'm not sure if this is from the same author as <a href="http://cow.physics.wisc.edu/~craigm/idl/ephem.html" rel="nofollow noreferrer">this library</a> - worth a read as it discusses the FITS format.</p>

CC BY-SA 3.0
2017-03-13T13:18:15.723Z
The python library is really good! Thanks a lot!
lindebear
CC BY-SA 3.0
2017-03-13T11:19:48.750Z
2017-03-13T11:19:48.750Z
Rory Alsop
<p>The Python package <a href="http://rhodesmill.org/skyfield/" rel="nofollow noreferrer">Skyfield</a> was written fairly recently, from scratch, by the <a href="https://stackoverflow.com/users/85360/brandon-rhodes">same person</a> who maintains <a href="http://rhodesmill.org/pyephem/" rel="nofollow noreferrer">PyEphem</a>. You may find helpful information inside there as well.</p>

<p>I had some difficulty reading a JPL kernel with a variant format, and was pointed to a home-brew python package that solved my problems. The whole thing <a href="https://space.stackexchange.com/a/19263/12102">is described here</a>.</p>

<p>If you look at the candid comments here: <a href="https://github.com/whiskie14142/spktype01" rel="nofollow noreferrer">https://github.com/whiskie14142/spktype01</a> you'll notice that the task is not always transparent.</p>

<p>There is also the helpful <a href="https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/spk.html" rel="nofollow noreferrer">SPK Required Reading</a>.</p>

CC BY-SA 3.0
2017-03-14T06:18:21.843Z
2017-03-14T06:18:21.843Z
2017-05-23T12:37:21.700Z
uhoh
<p>I'm currently trying to write a C++ library that makes accessing binary data from a JPL ephemeris file easier. So far I sifted through the web, trying to find a good and thorough documentation about what is actually stored in there and how to work with the data.</p>

<p>Does anybody know of a PDF/Book or something similar, that explains anything of that sort?</p>

<p>Thanks in advance!</p>

CC BY-SA 3.0
2017-03-19T18:03:50.420Z
I just ran across [this question](http://space.stackexchange.com/q/12506/12102) - you may find some of the various answers there helpful as well.
uhoh
<solar-system><ephemeris>
JPL DE Documentation
lindebear
# JPL DE Documentation

(Asked by: username_0 on 2017-03-13)

I'm currently trying to write a C++ library that makes accessing binary data from a JPL ephemeris file easier. So far I sifted through the web, trying to find a good and thorough documentation about what is actually stored in there and how to work with the data.

Does anybody know of a PDF/Book or something similar, that explains anything of that sort?

Thanks in advance!

**Tags:** solar-system, ephemeris
> **Comments:**
> **username_1**: I just ran across [this question](http://space.stackexchange.com/q/12506/12102) - you may find some of the various answers there helpful as well.  

---

## 2 answers

### Answer by username_2 on 2017-03-13. Score: 3 | Accepted answer

Be aware there are differing formats. SPK is the newer format - the older text format seems to be deprecated.

It's worth having a look at the documentation on [this jplephem python library](https://pypi.python.org/pypi/jplephem) as it explains the format reasonably well. If you do use SPK, you'll need to read all of [the documentation in NASA's SPK repository](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/FORTRAN/req/spk.html)

I'm not sure if this is from the same author as [this library](http://cow.physics.wisc.edu/~craigm/idl/ephem.html) - worth a read as it discusses the FITS format.

> **Comments:**
> **username_0**: The python library is really good! Thanks a lot!  

---

### Answer by username_1 on 2017-03-14. Score: 0

The Python package [Skyfield](http://rhodesmill.org/skyfield/) was written fairly recently, from scratch, by the [same person](https://stackoverflow.com/users/85360/brandon-rhodes) who maintains [PyEphem](http://rhodesmill.org/pyephem/). You may find helpful information inside there as well.

I had some difficulty reading a JPL kernel with a variant format, and was pointed to a home-brew python package that solved my problems. The whole thing [is described here](https://space.stackexchange.com/a/19263/12102).

If you look at the candid comments here: <https://github.com/whiskie14142/spktype01> you'll notice that the task is not always transparent.

There is also the helpful [SPK Required Reading](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/spk.html).


---

