- ephemd <perturbers> <objects> <observers> [options] [command]
- This is a simple, small and lightweight command-line driven ephemerides service for retrieving astrometrical information of small Solar System objects (SSOs).
- -h, --help
- Gives general summary about the command line options.
- --long-help, --help-long
- Gives a detailed list of command line options.
- --wiki-help, --help-wiki, --mediawiki-help, --help-mediawiki
- Gives a detailed list of command line options in Mediawiki format.
- Gives some version information about the program.
- Be more verbose during startup of ephemd.
- Be more quiet during startup of ephemd.
- -i, --stdio
- Instead of running in server mode, ephemd reads commands from and writes output to standard input and output, respectively.
- -p, --port <port>
- TCP/IP port in which ephemd listens for incoming connections. Default port is 9137.
- -c, --command <command> ...
- Executes the command <command> ... immediately after launching and loading ephemd data. Note that the <command> ... lasts up to the end of the command line, so one has to ensure that this option is the last which is passed to ephemd.
Parameters and regarding to orbital mechanics:
- -f, --planet-file, --planet-files <ephem_file> [<...>]
- List of input ephemerides of planets that acts as a perturber in the Solar System. The list of files lasts up to the next command line argument (starting with a dash or double dash) or up to the end of the command line. Hence, one may safely use wildcard patterns in order to specify multiple perturbs simultaneously.
- -b, --observer-file, --observer-files <ephem_file> [<...>]
- List of input ephemerides of observers. The list of files lasts up to the next command line argument (starting with a dash or double dash) or up to the end of the command line. Hence, one may safely use wildcard patterns in order to specify multiple observers simultaneously.
- -j, --object-file <file>
- Pre-formatted orbital elements of small Solar System objects. See also README and the script ./scripts/prep-2-dat2in.sh in the ephemd source package for more details about the format.
- -l, --leap-file, --leap-seconds-file <file>
- An IERS and IETF compliant version of data file describing the announcements of leap seconds. One of such files can be https://www.ietf.org/timezones/data/leap-seconds.list. You may have to update this file regularly (once or twice per year). Predictions further than the last announced leap seconds are expected to have no insertions. Check the expire date of this file accordingly.
- quit, exit, close
- Terminates the connection (server/client mode) or the program itself (in stdio mode).
- A brief summary about `ephemd` status.
- list observers
- Lists the available observers.
- set observer <name>
- Sets the observer to <name>.
- get observer
- Prints the name of the currently set observer.
- ephem <name> <time>
- Generates ephemerides for the object with <name> for the instance or interval defined by <time>. The <name> is taken from the input object file and by default (see `make prepare`) these are either the MPC designation numbers or the MPC temporal names. Official MPC names are not supported now. For instance, use `ephem 1234 ...` instead of `ephem Elyna ...`. The <time> is either a Julian Day instance or can have the format of <JD_start>:<step>:<JD_end> to generate a series of ephemerides. <JD_start>:<JD_end> is equivalent to <JD_start>:1.000:<JD_end>.
- query <RA>,<DEC> <radius> <time>
- Lists the objects with the respective ephemerides which has an apparent position within <radius> distance from the J2000 coordinate <RA>,<DEC>. <time> can either be an instance (in JDs) or an interval defined in the form of <JD_start>:<JD_end>. In the latter case, this command reports the JD when the object is (nearly) the closest to this point specified by <RA>,<DEC>. Currently, all of the angles (<RA>, <DEC> and <radius>) should be specified in degrees.