INPOP06. A new numerical planetary ephemeris

A. Fienga, H. Manche, J. Laskar, and M. Gastineau : 2008,
INPOP06. A new numerical planetary ephemeris.
Astronomy & Astrophysics, 477, pp. 315-327

preprint :


The orbital solutions of the Sun, the eight planets, the dwarf planet Pluto and the Moon and the libration of the Moon are available as binary data files.
The binary data files provide the rectangular coordinates (x,y,z) in kilometers of the bodies with respect to the International Celestial Reference Frame (ICRF). The librations are given in radians.

File format

These INPOP06 ephemeris files use the same internal format as the binary JPL DExxx ephemeris files ( : the coordinates in the data files are expressed as the coefficients of the Chebychev polynomials. These INPOP06 ephemeris files don't include the coefficients for the nutation. So these files could be read with the same programs (such as the JPL software package) which read the binary JPL ephemeris files.
The internal format is described in the paper :
David Hoffman : 1998,
A Set of C Utility Programs for Processing JPL Ephemeris Data,

Due to the problem of the endianess in the computer (order in which integers are stored as bytes in computer memory), the binary files are available into two formats :

  • little-endian for Intel x86, IA64 or Alpha based processors (and their clones).
  • big-endian for Motorola PowerPC, IBM Power or Sparc based processors (and their clones).
  • Usage

    To use these data files instead of the JPL ephemeris files, you only have to change the name of the files in your software program.
    If you use a program based on the "testeph.f" program from the JPL, then you may have to set the variable NRECL (and KSIZE if you don't use the subroutine FSIZER2). The prefered method is to read the beginning of the first record and then to compute the length of the records (same as KSIZE) with the libration's triplet (which contains the location, order and time-coverage of Chebychev polynomial).

    Binary data files - release INPOP06C

    time period
    (years from J2000)
    little-endian files
    (Intel or AMD x86, x86_64, IA64 or Alpha processors)
    big-endian files
    (Motorola PowerPC, IBM Power or Sparc processors)
    value of KSIZE
    (for the program "testeph.f")
    -100 to +100 (17 Mbytes) (17 Mbytes) 1876
    -1000 to +1000 (168 Mbytes) (168 Mbytes) 1876
    Previous releases are available from here


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    Last revision : 03 january 2008