Satellite Ephemeris File Release


Satellite Ephemeris: MAR085

Location: ssd.jpl.nasa.gov/pub/eph/satellites/nio/LINUX_PC/mar085.nio
Size(nio): 12 bytes

Enter SATEPHMERGE/13 02-Jun-2009 09:36: 1.621 linked 01-Apr-2008 09:16:24
Fit to data: MAR085.6
Ephemeris Version Number: 17
Timespan from JED  2415023.500(04-JAN-1900) to JED  2488071.500(03-JAN-2100)
File Epoch Julian Date: 2442983.50
Master Interval: 4.0000 Days
Equinox Reference Julian Date: 2451545.00
Planetary Ephemeris Number: DE-0421/LE-0421

Bodies on the File:

   Name     Number            GM             NDIV   NDEG   Model
   Phobos     401    7.091739680170039E-04     16     15   SATORB
   Deimos     402    1.009641595898490E-04      8     15   SATORB
   Mars       499    4.282837440030002E+04     16      7   SATORB
   System            4.282837521043814E+04

Additional Constants on the File:

  AU       1.495978706996262E+08   RADIUS   3.396000000000000E+03
  J402     1.956607465830782E-03   J403     3.147507554074059E-05
  J404    -1.538575483533000E-05   J405     5.726763004136751E-06
  J406    -4.855110957757139E-06   J407    -4.104314721127168E-06
  J408    -5.950945316885806E-07   POLTIM   2.451545000000000E+06
  ZACPL4   3.172516888281604E+02   ZDEPL4   5.440970827020242E+01
  DACPL4  -1.089657253405223E-01   DDEPL4  -5.793317199773752E-02
  WPL4     1.760765375475796E+02   WDP4     3.508919824964918E+02
  GMB      4.035032363095674E+05   GM6      3.794058520000016E+07
  GM5      1.267127648000003E+08   GMS      1.327124400409446E+11
  C40201   3.104209608136573E-10   S40201   2.948800476093854E-10
  C40202  -5.463219407577550E-05   S40202   3.158709200319611E-05
  C40301   4.108329934135620E-06   S40301   2.719466079272354E-05
  C40302  -5.447240601050437E-06   S40302   2.855955002123446E-06
  C40303   4.888057891148419E-06   S40303   3.566172683977448E-06
  C40401   4.000016367008860E-06   S40401   3.570166063899290E-06
  C40402  -2.129934470887725E-07   S40402  -2.008182886982658E-06
  C40403   3.858684129034953E-07   S40403  -1.154676158274252E-08
  C40404   6.544311209591252E-09   S40404  -2.719921965529053E-07
  C40501   4.141964360940282E-07   S40501   1.817987460862057E-06
  C40502  -6.955872223050639E-07   S40502  -1.886863024238513E-07
  C40503   1.094315923279241E-07   S40503   8.975121493770691E-09
  C40504  -3.613132311828388E-08   S40504  -2.633398994590623E-08
  C40505  -1.095650470178056E-08   S40505   9.306795249330532E-09
  401RAD   1.132000000000000E+01   401J2    1.005800000000000E-01
  401C22   1.591000000000000E-02   401LIB   1.189424542401034E+00
  4K2_0    1.520000000000000E-01   401PSI  -3.458126947205846E-01


Chebyshev interpolation error:  2.000 meters

Release to: Horizons/NAIF                      Time: 15-Jan-2010 08:43:29

Preparer: R. A. Jacobson

Comments:
Ephemeris for Martian satellites from fit to all data.
Work is described in AJ 139 (2010) 668-679.

 THE ORBITS AND MASSES OF THE MARTIAN SATELLITES AND THE LIBRATION OF PHOBOS

                             R. A. Jacobson
        Jet Propulsion Laboratory, California Institute of Technology,
             4800 Oak Grove Drive, Pasadena, CA 91109-8099
                     robert.jacobson@jpl.nasa.gov

                              ABSTRACT

This paper reports on an update to the orbits and masses of the Martian
satellites, Phobos and Deimos.  We obtained the orbits by fitting a numerical
integration to all available Earthbased astrometry through the opposition of
2003, spacecraft imaging observations through 2007, and the Doppler tracking
of the Viking and Phobos 2 spacecraft; the Doppler data provide information 
on the satellite masses.  Our dynamical model included the figure acceleration
due to a librating Phobos; we determined the amplitude of the forced libration.
We also took into account the secular acceleration of Phobos due to the tide
that it raises on Mars and estimated the Martian tidal quality factor Q.
We provide an assessment of the accuracy of the orbits and a geometrical
description of the orbits in the form of mean elements.