Downloads and Updates Software Registration Contact Information Shopping Cart

by Standish, et. al.
$24.95


Add to cart

The JPL Planetary and Lunar Ephemerides on CD-ROM
contains three different Jet Propulsion Laboratory Planetary and Lunar Ephemerides (DE200, DE405, and DE406) along with associated reading and interpolating routines. These allow a competent user to obtain the rectangular coordinates of the sun, moon, and nine major planets by means of a subroutine written in standard FORTRAN. The data and programs should be viewed by the potential user as a "tool box" for one skilled in computer programming and knowledgeable about astronomical computing.


DE200 : (includes nutations but not librations)

JED 2305424.5 (1599 DEC 09) to JED 2513360.5 (2169 MAR 31)

This ephemeris has been the basis of the Astronomical Almanac since 1984. It is based upon the dynamical equator and equinox of J2000 (see Standish, 1982 and Standish, 1990).

DE405 : (includes both nutations and librations)

JED 2305424.50 (1599 DEC 09) to JED 2525008.50 (2201 FEB 20)

The latest JPL ephemeris, created in May-June, 1997. DE405 is based upon the International Celestial Reference Frame (ICRF), the newly-adopted reference frame of the International Astronomical Union (IAU). The frames of DE200 and DE405 differ by no more than about 0.01 arcseconds.

DE406 : the New "JPL Long Ephemeris" (includes neither nutations nor librations)

JED 0625360.50 (-3000 FEB 23) to 2816912.50 (+3000 MAY 06)

DE406 is the same ephemeris as DE405, though the accuracy of the interpolating polynomials has been lessened (interpolation on the 64-day mesh points remains exact, however). For DE406/LE406, the interpolating accuracy is no worse than 25 meters for any planet and no worse than 1 meter for the moon.


The following is additional information from the read me files contained on the CD-ROM itself:

        JPL PLANETARY AND LUNAR EPHEMERIDES

                           E M Standish, JPL


Copyright 1997, The Jet Propulsion Laboratory, California Institute of
Technology, All Rights Reserved.

Published by Willmann-Bell, Inc., P.O. Box 35025, Richmond, VA 23235.

The programs and data provided in this CD-ROM are based upon on a long-term and
ongoing scientific program of analysis and refinement. What is presented here
has been tested with care but is not guaranteed for any particular purpose.
Neither The Jet Propulsion Laboratory nor Willmann-Bell, Inc. offer any
warranties or representations, nor do they accept any liabilities with respect
to the contents of this CD-ROM.

============================== I. Introduction  ==============================

 This CD contains JPL Planetary and Lunar Ephemerides along with associated
 reading and interpolating routines. These allow a competent user to obtain
 the rectangular coordinates of the sun, moon, and nine major planets by means
 of a subroutine written in standard fortran.

 We suggest for the more casual user, JPL's interactive "telnet" site,
 "Horizons", which provides a wide variety of astronomical information and
 which uses the full precision of our ephemerides. See Section X.

 The final goal of the installation process is the successful execution of the
 main program "TESTEPH.F". This program reads and interpolates planetary and
 lunar coordinates from a binary direct-read ephemeris file and compares these
 results against corresponding numbers produced at JPL. "TESTEPH.F" uses the
 subroutines which are of eventual interest to the user.

 It is strongly suggested that a potential user first read through this README
 in its entirety. This will provide an idea of what is involved in both the
 installation and in the usage of the ephemeris package.

 This README contains the following sections:

   I. Introduction
   II. How to Proceed
  III. Brief Description of Items on the CD
   IV. Available Ephemerides
   V. Software Description
   VI. Software Usage
  VII. Constants on the Ephemeris File
  VIII. Documentation and References
   IX. C-Versions of the Software
   X. Horizons - JPL's Interactive Ephemeris System
   XI. Format of the Ephemeris Files
  XII. Assistance


============================  II. How to Proceed  ===========================

There are two different paths:

 For UNIX-based users,

  the actual ephemeris files are available in binary form, ready for immediate
  installation on the user's computer or for use directly from the CD itself.

 For all NON-UNIX-based users,

  the ephemeris is supplied in ASCII format and must be converted (a one-time
  only process) into binary format for installation; software is supplied for
  this conversion. (Sorry, we have tried to export binary files for other
  types of platforms, but the lack of uniformity from one computer and/or
  compiler to the next made this too difficult.)

  Therefore, the non-UNIX-based user, using the program "ASC2EPH", must create
  a binary file by combining the desired choices of "ascSYYYY.XXX" preceded by
  the proper corresponding "HEADER.XXX".


 ALL USERS,

  must tailor the program "TESTEPH" according to the instructions in
  "USRGUIDE", paying attention to the parts about "NRECL" and "FSIZER".

  Run "TESTEPH" as described in "USRGUIDE".

 If "TESTEPH" works, you are done: "TESTEPH" uses the subroutines of interest
 (which are described in Sections V and VI).


===================  III. Brief Description of Items on the CD  ==============

 "USRGUIDE"   : User's Guide containing instructions for obtaining and/or
          creating the binary direct-read ephemeris file, tailoring the
          software, and testing the software package.

 "TESTEPH"   : The main program which uses, and therefore tests, the reading
          and interpolating subroutines. This program compares the
          results with similar runs made at JPL in order to ensure
          that the ephemeris is installed and being read correctly.

          The reading and interpolating subroutines included in
          "TESTEPH", along with the ephemeris file(s) themselves, are
          the items which are of eventual interest to the user.

 "TESTPO.XXX"  : Test results computed at JPL using the ephemeris DEXXX.
          These are input by the program "TESTEPH" and are used for
          testing the ephemeris installation. There is a different
          "TESTPO" for each different ephemeris; they must match or the
          test will not work correctly.

 "BINMERGE"   : Program to merge two adjoining binary ephemerides.

 "BINSHORT"   : Program to extract a portion of an ephemeris from a larger
          file.

 for UNIX users
 --------------

 "unix.XXX"   : The full binary ephemeris file of JPL Ephemeris DEXXX.
          The file may be used straight from the CDrom by the
          program "testeph", or it may be copied onto a hard disk.
          A shorter-span ephemeris may be extracted from a longer
          one using the program, "BINSHORT.F".

 for non-UNIX users
 --------------

 "ASC2EPH.F"  : A one-time conversion program which converts the ephemeris
          from ASCII format into binary form (described in "USRGUIDE").

 "ascSYYYY.XXX" : ASCII ephemeris files from JPL Ephemeris DEXXX, covering 20
          years, starting in the year SYYYY (where "S" is "m" or "p",
          indicating "-" or "+"; i.e., for "BC" or "AD"). The 20-year
          blocks may be converted separately into binary ephemeris
          files using "ASC2EPH", or they may be combined into a single
          ASCII file and then converted into a single binary file.
          Subsequently, separate binary files may be merged into a
          single ephemeris file using the program, "BINMERGE.F". Also,
          a shorter-span ephemeris may be extracted from a longer one
          using the program, "BINSHORT.F".

 "header.XXX"  : Header info for ephemeris deXXX, needed by "ASC2EPH.F".


======================= IV. Available Ephemerides  ==========================

DE200 : (includes nutations but not librations)

   JED 2305424.5 (1599 DEC 09) to JED 2513360.5 (2169 MAR 31)

   This ephemeris has been the basis of the Astronomical Almanac since
   1984. It is based upon the dynamical equator and equinox of J2000
   (see Standish, 1982 and Standish, 1990).


DE405 : (includes both nutations and librations)

   JED 2305424.50 (1599 DEC 09) to JED 2525008.50 (2201 FEB 20)

   Our latest ephemeris, created in May-June, 1997. DE405 is based upon the
   International Celestial Reference Frame (ICRF), the newly-adopted reference
   frame of the International Astronomical Union (IAU). The frames of DE200
   and DE405 differ by no more than about 0.01 arcseconds.


DE406 : the New "JPL Long Ephemeris" (includes neither nutations nor librations)

   JED 0625360.50 (-3000 FEB 23) to 2816912.50 (+3000 MAY 06)

   DE406 is the same ephemeris as DE405, though the accuracy of the interp-
   olating polynomials has been lessened (interpolation on the 64-day mesh
   points remains exact, however). For DE406/LE406, the interpolating
   accuracy is no worse than 25 meters for any planet and no worse than
   1 meter for the moon.

 Ephemeris items            de200  de405   de406
 ---------------            ------  ------  -------

UNIX binary            :   55 Mb   62 Mb   199 Mb

ASCII (each 20-year block)    :   5.2 Mb  6.4 Mb


========================= V. Software Description  ===========================

The software package (apart from the programs used to initially construct the
ephemeris, ASC2EPH, BINMERGE, and BINSHORT) consists of a main test program
("TESTEPH") which uses the reading and interpolating routines in order to
retrieve the ephemeris data and to compare the results against the test data.

Two of the subroutines contained in "TESTEPH" are of primary interest to the
user: "PLEPH" and "SELCON". Three others, "CONST", "DPLEPH", and "STATE" may
also be useful.

  PLEPH : Get the state vector (position and velocity) of one body with
       respect to another at any given time within the interval covered
       by the ephemeris.

  SELCON : Retrieve values of user-requested constants on the ephemeris file.

  CONST : Retrieve values of all of the constants on the ephemeris file.

  DPLEPH : Same as PLEPH, but with increased precision in the input time.

  STATE : Read and interpolate the ephemeris file. (Called by PLEPH).


==========================  VI. Software Usage  ==============================

 PLEPH ******** subroutine PLEPH( tdb, npl, nctr, pv) **********

  Input
  -----
     tdb [d.p.] : julian ephemeris date
     npl [int.] : planet number
     nctr [int.] : center number

       identifications for "npl" and "nctr"
       ------------------------------------
       1 = mercury      8 = neptune
       2 = venus       9 = pluto
       3 = earth      10 = moon
       4 = mars       11 = sun
       5 = jupiter     12 = solar-system barycenter
       6 = saturn      13 = earth-moon barycenter
       7 = uranus      14 = nutations in longitude and obliquity
                  15 = librations (if they exist on the file)
         (for nutations and librations, nctr=0)
  Output
  ------
     pv(6) [d.p.] : x,y,z,x-dot,y-dot,z-dot [au, au/day]
          for nutations, d(psi), d(eps), d(psi)-dot, d(eps)-dot
                 [rads, rads/day]
          for librations, (Euler angles and rates, w.r.t. the ephemeris
                  reference frame)  [rads, rads/day]

 Note : Over the years, different versions of PLEPH have had a fifth argument:
 sometimes, an error return statement number; othertimes, a logical denoting
 whether or not the requested date is covered by the ephemeris. We apologize
 for this inconsistency; in this version, we use only the four necessary
 arguments and do the testing outside of the subroutine.


 SELCON ******** subroutine SELCON ( nams, nmbr, vals) **********

  Input
  -----
  nams(nmbr) [char*6] : names for which values are requested (a list of the
             possible choices is given below)
  nmbr [int.]     : the number of names in 'nams'

  Output
  ------
  vals(nmbr) [d.p.]  : values corresponding to the names in 'nams'


 CONST ******** subroutine const(nmv,vlv,sss,nrv) **********

  Input  (none)
  -----

  Output
  ------
   nmv(nrv) [char*6] : names of the constants used in creating the ephemeris
   vlv(nrv) [d.p.]  : values of the constants used in creating the ephemeris
   nrv [int.]    : number of names and values in nmv and vlv
   sss(3) [d.p.]   :  sss(1) : starting jed of the ephemeris file
              sss(2) : ending jed of the ephemeris file
              sss(3) : number of days covered by each block
                   of Chebychev coefficients


 STATE ******** subroutine state(jed,list,pv,nut,*) **********

 [This subroutine is identical to that provided in the past; it is still
  provided to give previous users compatibility; it is not recommended for use
  by first-time users.]

 DPLEPH ******** entry DPLEPH( tdb2, npl, nctr, pv) **********

 This entry is identical to "PLEPH", except that the input time, tdb2, is
 doubly-dimensioned for increased precision [ double precision tdb2(2) ].

          Any combination of tdb2(1)+tdb2(2) which falls within
          the time span on the file is a permissible epoch.

          For ease in programming, the user may put the entire
          date into tdb2(1) and set tdb2(2)=0.

          However, for maximum interpolation accuracy, set
          tdb2(1) equal to the most recent midnight at or before
          interpolation epoch (i.e., xxxxxxx.5d0) and set
          tdb2(2) equal to the remaining fractional part of the
          day.

          As an alternative, it may prove convenient to set
          tdb2(1) equal to some fixed epoch, and set tdb2(2) equal
          to the time since that epoch.


====================== VII. Constants on the Ephemeris File  =================

The following is a partial list of constants found on the ephemeris file:

 DENUM      Planetary ephemeris number.
 LENUM      Lunar ephemeris number.
 TDATEF, TDATEB Dates of the forward and backward integrations
 CLIGHT     Speed of light (km/s).
 AU       Number of kilometers per astronomical unit.
 EMRAT      Earth-Moon mass ratio.
 GMi       GM for ith planet [au**3/day**2].
 GMB       GM for the Earth-Moon Barycenter [au**3/day**2].
 GMS       GM for the Sun (= k**2) [au**3/day**2].
 X1, ..., ZD9  Initial conditions for the numerical integration,
         given at "JDEPOC", with respect to "CENTER". [au and au/day]
 JDEPOC     Epoch (JED) of initial conditions, normally JED 2440400.5.
 CENTER     Reference center for the initial conditions.
         (Sun: 11, Solar System Barycenter: 12)
 RADi      Radius of ith planet [km].
 MA0001...MA0324 GM's of asteroid number 0001 ... 0234 [au**3/day**2].
 PHASE      The phase angle of the moon's rotation.
 LOVENO     The Love Number, k2, for the moon.
 XL...ZDL    Initial conditions of the libration angles.


===================== VIII. Documentation and References  ====================

A copy of the JPL Inter Office Memorandum describing DE405 and DE406 is
available in TeX and the figures are available in Postscript, both available
at ftp://navigator.jpl.nasa.gov/pub/ephem/export/de405.iom/

and all 8 Postscript figures and the de405iom.ps file itself must be retrieved:

08/26/98 12:00AM 103,528 de405fig1.ps
08/26/98 12:00AM 107,870   de405fig2.ps
08/26/98 12:00AM  50,259   de405fig3.ps
08/26/98 12:00AM  46,775   de405fig4.ps
08/26/98 12:00AM 167,676   de405fig5.ps
08/26/98 12:00AM  47,201   de405fig6.ps
08/26/98 12:00AM 114,529   de405fig7.ps
08/26/98 12:00AM 110,497   de405fig8.ps
08/26/98 12:00AM 960,524   de405iom.ps
08/26/98 12:00AM  38,796   de405iom.tex


The following references also apply to the JPL Ephemerides:

 Newhall, X X, Standish, E.M. and Williams, J.G.: 1983, "DE102: a numerically
  integrated ephemeris of the Moon and planets spanning forty-four centuries",
  Astronomy & Astrophysics, vol. 125, pp. 150-167.

 Standish, E.M.: 1982, "Orientation of the JPL Ephemerides, DE200/LE200, to the
  Dynamical Equinox of J2000", Astronomy & Astrophysics, vol. 114, pp. 297-302.

 Standish, E.M.: 1990, "The Observational Basis for JPL's DE200, the planetary
  ephemeris of the Astronomical Almanac", Astronomy & Astrophysics, vol. 233,
  pp. 252-271.

======================= IX. C-Versions of the Software  ======================

There are C-versions of the software, written by outside users. Access to them
is described in the file, "/usr1/ftp/ephem/export/README";, on the anonymous ftp
site, ftp://navigator.jpl.nasa.gov/pub/ephem/export/C-versions/

And there are two subfolders to examine:


hoffman
kourosh

See the "README" file in the ftp://navigator.jpl.nasa.gov/pub/ephem/export/README for
details regarding external exportable user data for the JPL ephemeris progams.

======================= IX. C-Versions of the Software  ======================

There are C-versions of the software, written by outside users. Access to them
is described in the file, "/usr1/ftp/ephem/export/README", on the anonymous ftp
site, "navigator.jpl.nasa.gov"]


============= X. Horizons : JPL's Interactive Ephemeris System  ==============

 Horizons, JPL's Interactive Ephemeris System, is now being made available as a
 WWW site (July, 1997): http://ssd.jpl.nasa.gov

 At present, the on-line ephemeris system is a telnet service. From a telnet-
 capable machine, telnet to "ssd.jpl.nasa.gov 6775", where 6775 is a port. From
 within a web-browser, such as Netscape, type "telnet://ssd.jpl.nasa.gov:6775".
 The system will start automatically. No user-ID or password is required.

 Reasons for being denied access are:

   1) You typed the wrong machine address or port number.
   2) The maximum allowed number of users are already connected. Try later.
   3) The system is down (should be rare; 24/7 service is planned)

 If a user-name/password is requested, you did not specify the port number.

 The system will automatically negotiate the terminal type. If this fails
 (common), the default will be a vt100 display.

 The system will also attempt to determine your window size. If this fails
 also common), it will default to a 24 row by 79 column screen display. If
 this is inappropriate, and your display paging is choppy, manually set your
 screen size by using the command "TTY {rows} {columns}", where {rows} and
 {columns} are replaced by appropriate integers.

 Address inquires concerning Horizons to : jon.giorgini@jpl.nasa.gov


==================== XI. Format of the Ephemeris Files  ======================

 It is not necessary to know the information contained in this section in order
 to install and use the JPL ephemerides. Some users, however, have requested
 parts of the following information, so it is provided here.

 The first two records of the binary files contain header information; the rest
 of the records contain the main ephemeris data. Each ephemeris data record
 contains a block of 32 days (DE200 and DE405) or of 64 days (DE406) of
 ephemeris polynomials.

 For the ascii versions, the main ephemeris data come in 20-year pieces; each
 piece is composed of a number of 32-day blocks or of 64-day blocks.

 The first two words in each data record contain the JED of the beginning of the
 data in the block and the JED of the ending of the data in the block.
 The remaining data are chebychev position coefficients for each component of
 each body on the tape. The chebychev coefficients for the planets represent
 the solar system barycentric positions of the centers of the planetary systems.

 The roadmap to the contents of the 32-day or 64-day blocks is given by
 "pointers", contained in the first record of the binary files or in the
 "GROUP 1050" of the ascii headers. The pointers consist of 3 sets of 13
 integers each. (In the binary version, the first 12 members of the three sets
 are stored together; the 13th members of each set are stored later in the
 record.) The 13 triplets give information about the location, order and, time-
 coverage of the chebychev polynomials corresponding to the following 13 items:

    Mercury
    Venus
    Earth-Moon barycenter
    Mars
    Jupiter
    Saturn
    Uranus
    Neptune
    Pluto
    Moon (geocentric)
    Sun
    Nutations
    Librations

 For the ith item, pointer(1,i) is the starting location in each data record of
 the chebychev coefficients; pointer(2,i) is the number of coefficients per
 component; pointer(3,i) is the number of complete sets of coefficients in each
 data record.

  For example, the pointers for DE405 look like,

   3  171  231  309  342  366  387  405  423  441  753  819  899
  14  10  13  11   8   7   6   6   6  13  11  10  10
   4   2   2   1   1   1   1   1   1   8   2   4   4

  For the moon, starting in the 441st double precision word, there are 13
  coefficients for the x-coordinate which apply over the first 4 (32/8) days of
  the 32-day interval covered by this block of data. The next 13 coefficients
  are for the y-coordinate; then, 13 for z. Seven similar sets follow for the
  moon, making 13x3x8=312 words in all. The coefficients for the Sun follow
  the moon, starting in the 753rd location.

 There are three cartesian components (x, y, z), for each of the items #1-11;
 there are two components for the 12th item, nutations : d(psi) and d(epsilon);
 there are three components for the 13th item, librations : three euler angles.
 Velocites are obtained by interpolating the position polynomials.

 Planetary positions are given in kilometers on the file, but are translated
 automatically into AU's by the software unless overridden by the user. The
 nutations and librations are given in radians.

 DE200 is nominally with respect to the mean equator and equinox of J2000,
 coinciding with the origin of FK5. DE405 is based upon the Intermational
 Celestial Reference Frame (ICRF), the newly-adopted reference frame of the
 International Astronomical Union (IAU). The frames of DE200 and DE405 differ
 by no more than about 0.01 arcseconds.