Heliospheric Coordinate Systems


Space Plasma Group
Astronomy Unit

 This website gives an overview and reference to the most common coordinate systems currently used in space science. While coordinate systems used in near-Earth space physics have been described in previous work we extend that description to systems used for physical observations of the Sun and the planets and to systems based on space craft location. For all systems we define the corresponding transformation in terms of Eulerian rotation matrices. We also give first order Keplerian elements for planetary orbits and determine their precision for the period 1950-2050 and describe methods to improve that precision. We also determine the Keplerian orbital elements for most major interplanetary missions and discuss their precision. We also give reference to a large set of web-sources relevant to the subject.

2002/02/07: Paper now published as
                    M.Fraenz and D.Harper, Heliospheric Coordinate Systems, Plan.Space Sci., 50, 217-233 (Feb 2002)
                    see Planetary & Space Science Web Page.
2002/02/12: Correction of paper and software available on this website.
2017/03/17: New correction of paper available on this website.

Corrected version of the article published in Plan.Space Sci.:
  HTML-Version   PDF-Version

If would like to submit comments or corrections,
please email Markus Fraenz: fraenz@linmpi.mpg.de

Subfolders containing  plots showing the precision of Keplerian approximation to orbits:

   Orbitplots    for planetary orbits.
   Trajplots      for space craft trajectories rel. to NSSDC web data.
   Trajplots2    for space craft trajectories rel. to NSSDC ftp data (.eq files).
   Trajplots3    for space craft trajectories rel. to NSSDC/JPL state vectors.

Subfolder containing IDL software   implementing the transformations.

Subfolder containing All Data  from the paper in ascii tables.

Links to other sites on Coordinate Systems:

AGU Reference Shelf: Charles F. Yoder's article on astrometry
American National Space Science Data Center(NSSDC)

American Nautical Almanac Office
APL Superdarn on AACGM
K.Burnett's site on planetary orbits
Centre de Donnees de la Physique des Plasmas: J.-C. Kosik's MAGLIB 
HM Nautical Almanac Office
Institut de Mecanique Celeste
International Earth Rotation Service (IERS)
JPL Horizons System and DE200
NSSDC Modelweb on CGM
Oulu University: spaceweb on CGM
RAL: M.Hapgood's page on geophysical coordinates
Ulysses orbital elements at ESA
Voyager orbital elements at JPL

Markus Fraenz (fraenz@linmpi.mpg.de) 2002-03-12