XEphem

History

Brandon Rhodes 03996601fc Remove stale “RCS” comments from text files perl -pi -0777 -e 's/# For RCS .\n//g' / perl -pi -0777 -e 's/# .... .RCSfile.\n//g' /		2021-08-23 13:22:23 -04:00
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Makefile	Remove stale “RCS” comments from text files	2021-08-23 13:22:23 -04:00
README	Remove stale “RCS” comments from text files	2021-08-23 13:22:23 -04:00
print.c	Remove stale “RCS” comments from C code	2021-08-23 13:19:28 -04:00
sample.res	Initial import from “xephem-4.0.0.tgz” archive	2021-02-08 15:05:21 -05:00
xedb.c	Remove stale “RCS” comments from C code	2021-08-23 13:19:28 -04:00

README

xedb is a command line program that reads lines of sources in .edb format on
stdin and writes ephemeris data for each source on stdout. The output format
is the same as xephemdbd; please see it's README for details.

Several operating parameters are extracted from the same resource file
used by XEphem. Although not linked with X libraries, xedb looks for this
file using the same rules as XEphem and should make sharing these parameters
between programs easy. The resources used, and defaults if not found for those
which are optional, are:

XEphem.Lat       d:m:s north, required
XEphem.Long      d:m:s west, required
XEphem.Elevation m above mean sea level, required
XEphem.Pressure  1010 hPa, optional
XEphem.Temp      10 C, optional
XEphem.TZone     0 hours behind UTC, optional
XEphem.Equinox   2000.0, optional

xedb also has a few command line arguments as follows:

  -j j : set time to JD j, else use current host
  -r f : use XEphem resource file f, else round up the usual suspects
  -t   : generate topocentric, else geocentric
  -v   : verbose

To build xedb, put the source in tools/xedb below the XEphem source code
directory and type make. The libastro library is required and should be
in ../../../../libastro.

After building xedb, run a quick sanity test as follows:

1. set up a trial reource file, sample.res, containing this:

XEphem.Lat:       42:29:40
XEphem.Long:      92:20:20
XEphem.Elevation: 259.1
XEphem.Pressure:  1010
XEphem.Temp:      10
XEphem.TZone:     6:00:00
XEphem.Equinox:   2000

2. run this:

echo 'C/2002 C1 (Ikeya-Zhan,e,28.1206,93.3718,34.6666,51.27566,,0.9901111,0, 3/18.9784/2002, 1/01/2000,g7.5,4,0' | xedb -j 2452330.50000 -v -t -r sample.res

3. the output should be this:

Using resource file sample.res
  mjd    2002.15068 AD
  lat      42.49444 °
  lng     -92.33889 °
 temp      10.00000 °C
press    1010.00000 hPa
 elev     259.10000 m
   tz       6.00000 hrs behind UTC
epoch    2000.00000 AD
  equ          Topo
Processing: C/2002 C1 (Ikeya-Zhan,e,28.1206,93.3718,34.6666,51.27566,,0.9901111,0, 3/18.9784/2002, 1/01/2000,g7.5,4,0

C/2002 C1 (Ikeya-Zhan e      0:53:18.09  -3:11:56.8   6.52    0  65:12:36 -14:10:09  1.233  0.719  80   3:15:59.8  26:28:51 237:18:40 14:54  94:11 20:44 44:13  2:35 266:18


Elwood Downey
ecdowney@clearskyinstitute.com