JPLEPHTEST
Name
JPLEPHTEST
Author
Craig B. Markwardt, NASA/GSFC Code 662, Greenbelt, MD 20770
craigm@lheamail.gsfc.nasa.gov
UPDATED VERSIONs can be found on my WEB PAGE:
http://cow.physics.wisc.edu/~craigm/idl/idl.html
Purpose
Test JPLEPHTEST with JPL test data set
Major Topics
Planetary Orbits, Interpolation
Calling Sequence
JPLEPHTEST, EPHFILE, TESTFILE
Description
JPLEPHTEST tests the JPLEPHINTERP procedure for precision. In
order to function, you must have a JPL ephemeris test data set.
The test data set testpo.405 is available in
ftp://idlastro.gsfc.nasa.gov/pub/data
The procedure opens and reads the test set, which contains
precomputed data. Every tenth value is printed on the screen.
Any deviations that exceed 1.5d-13 AU = 1.5 cm are reported.
The columns are labelled according to the input file, except for
the final column, which is the deviation between the input file
and the computed value.
Parameters
EPHFILE - a scalar string, specifies the name of the ephemeris
file, in FITS format. JPLEPHTEST will look in the directory
$ASTRO_DATA for the file if it is not in the current directory.
TESTFILE - a scalar string, specifies JPL test data set to compare
against. JPLEPHTEST will look in the directory
$ASTRO_DATA for the file if it is not in the current directory.
Example
Test JPL DE200 and DE405 ephemerides. Assumes files are in the
current directory.
JPLEPHTEST, 'JPLEPH.200', 'testpo.200'
JPLEPHTEST, 'JPLEPH.405', 'testpo.405'
References
JPL Export Ephemeris FTP Site
ftp://ssd.jpl.nasa.gov/pub/eph/planets/
(see test-data/ for test data sets)
HORIZONS, JPL Web-based ephermis calculator (Ephemeris DE406)
http://ssd.jpl.nasa.gov/horizons.html
See Also
JPLEPHREAD, JPLEPHINTERP, JPLEPHTEST
Modification History
Written and Documented, CM, Jun 2001
Removed TRANSREAD, improved output, improved docs, CM, 9 Jul 2001