Content-type: text/html Man page of ephcom_eph2eph

ephcom_eph2eph

Section: ephcom2 command (1)
Updated: August 2011
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NAME

ephcom_eph2eph - merges two JPL binary ephemeris files to a third  

SYNOPSIS

ephcom_eph2eph input1 input2 output [startJD [stopJD]]
 

DESCRIPTION

Merges two JPL binary ephemeris files into a third binary ephemeris file.

input1
first binary ephemeris input file.
input2
second binary ephemeris input file. If input1 is the same as input2, ephcom_eph2eph will "scrub" the input ephemeris file to remove any inconsistencies. (See the intentional side effects mentioned below.)
output
the merged binary ephemeris file.
startJD
optional Julian Day at which to begin (note that ephcom_eph2eph must begin at an integral ephemeris data block boundary of typically 32 or 64 days, so it will probably start soon before the desired startJD). If not specified, all of both input files are read.
stopJD
optional Julian Day at which to stop (note that ephcom_eph2eph must end at an integral ephemeris data block boundary of typically 32 or 64 days, so it will probably end soon after the desired stopJD). If not specified, both input files are read to the end.

ephcom_eph2eph reads in two JPL binary ephemeris files and merges them into a third binary ephemeris file. The first two files must have the same JPL ephemeris number, Earth-Moon Mass Ratio (EMRAT), distance of an AU (in kilometers), number of constants in the header, and number of coefficients in a data block. Otherwise, they were not generated from the same ephemeris and are not compatible.

The two input files must be adjacent in time, with either one ending exactly where the other begins, or with some overlap between the end of the first file and the beginning of the second. Otherwise, there would be a gap with unknown coefficients for a date span.

As an intentional side effect, ephcom_eph2eph will remove several formatting errors in the original JPL files: the last data block (a copy of the second to last block) is not repeated; ASCII start and stop dates in the header are corrected; ipt[*][0] and lpt[0] contain the next possible coefficient location rather than 0 (this is the preferred format, as communicated by JPL's Myles Standish to Paul Hardy); data in unused portions of the header is set to all zeroes.  

AUTHOR

Written by Paul Hardy, ephemeris.com. Revised and updated by Alan W. Irwin  

REPORTING BUGS

Report bugs to <airwin@users.sourceforge.net>.  

COPYRIGHT

Copyright © 1994-2004 Paul Hardy
Copyright © 2011 Alan W. Irwin

This is free software; you can redistribute it and/or modify it under the terms of version 2.1 of the GNU Lesser General Public License as published by the Free Software Foundation.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this package; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA or see http://www.gnu.org/copyleft/lesser.html on the web.  

SEE ALSO

ephcom_asc2eph(1), ephcom_concatenate.sh(1), ephcom_eph2asc(1), ephcom_ephcmp(1), ephcom_ephcoeff(1), ephcom_headcmp(1), ephcom_testeph(1), ephcom_vtransit(1)


 

Index

NAME
SYNOPSIS
DESCRIPTION
AUTHOR
REPORTING BUGS
COPYRIGHT
SEE ALSO

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Time: 19:46:22 GMT, August 16, 2011