mirror of https://github.com/XEphem/XEphem.git
175 lines
6.0 KiB
Plaintext
175 lines
6.0 KiB
Plaintext
XEphemdbd is a filter to find astronomical objects within a given field of
|
|
view. All files accessable to XEphem are searched. It can also be used as a
|
|
deamon to feed other processes, or from a cgi-bin script (see sample
|
|
xephemdbd.html and xephemdbd.pl).
|
|
|
|
To build xephemdbd, first build XEphem then just type 'make' here.
|
|
|
|
To install on a web server, see INSTALL.
|
|
|
|
As a filter, xephemdbd reads lines of input from stdin until EOF. Each line
|
|
defines a center RA and Dec, field of view and observing circumstances. Each
|
|
request yields lines of output of all objects falling within the field on
|
|
stdout. The search may be restricted to various classes of objects, may be
|
|
topocentric or geocentric, astrometric or apparent. The output format may be
|
|
in .edb format or in a column-based text format.
|
|
|
|
As a daemon, input may come from a file designated with the -i command
|
|
argument. This file is opened R/W in anticipation of it being a fifo to
|
|
prevent xephemdbd from seeing EOF as clients using the fifo come and go.
|
|
xephemdbd will exit if no more requests appear within 30 minutes (or a time
|
|
as set using -t). Xephemdbd reads all *.edb files into memory one time at
|
|
start-up, then forks a process to perform each search which includes a
|
|
separate output file specification. If the underlying system supports COW,
|
|
copy-on-write, this forking scheme allows the data files to only be read
|
|
into memory one time and never copied.
|
|
|
|
Usage: xephemdbd [options]:
|
|
-c <dir> alternate catalogs directory;
|
|
default is /usr/local/xephem/catalogs
|
|
-d do not fork/exit as a daemon process
|
|
-f do not try to use field star catalogs
|
|
-i <file> open file R/W for input; default is stdin
|
|
-l <file> lock file; default is /tmp/xephemdbd.pid
|
|
-m <file> dir of moon models; default is /usr/local/xephem/auxil
|
|
-t <secs> max idle minutes, 0=forever. default is 30
|
|
-v verbose to stderr
|
|
|
|
|
|
|
|
Each input request is one line of text, read from stdin (or where ever -i
|
|
is set). Args are separated by commas, formatted as follows:
|
|
|
|
[>file,]outputmode,types,year,RA,Dec,FOV,Mag[,lat,long,elev]
|
|
|
|
>file:
|
|
|
|
Optional. If the first argument begins with '>', it names an output
|
|
file. xephemdbd will fork a child process to handle this request,
|
|
write the output to this file, and the child will exit.
|
|
|
|
if this argument is missing, the output goes to stdout
|
|
|
|
outputmode: sum of:
|
|
|
|
1 columnar text (see below),
|
|
else edb format
|
|
2 topocentric (requires lat/long/elev),
|
|
else geocentric
|
|
4 apparent@year (requires lat/long/elev),
|
|
else astrometric@2000
|
|
8 include header detail
|
|
|
|
object types: sum of:
|
|
|
|
1 planets
|
|
2 elliptical
|
|
4 parabolic
|
|
8 hyperbolic
|
|
16 stars
|
|
32 clusters
|
|
64 galaxies
|
|
128 other deep sky
|
|
256 PPM/SAO/HD
|
|
512 GSC
|
|
|
|
year:
|
|
|
|
the desired time for the ephemerides to be calculated, as decimal year.
|
|
|
|
RA, Dec:
|
|
|
|
center of the field of view, radians
|
|
|
|
FOV:
|
|
|
|
diameter of field of view, radians
|
|
|
|
Mag:
|
|
|
|
limiting magnitude, that is, only report object at least this bright
|
|
|
|
lat, long, elev;
|
|
|
|
latitude and longitude of observing site, in radians. longitude is
|
|
+eastwards. elev is the height abov sea level, in meters. These
|
|
|
|
fields are only necessary if outputmode specified topocentric or
|
|
apparent place coordinates.
|
|
|
|
|
|
The .edb output format is for feeding XEphem. Therefore for non-fixed objects
|
|
the values are the orbital elements, not ephemerides.
|
|
|
|
The .txt format is for feeding web pages or some other application. It is a
|
|
true ephemerides and is intended primarily to be easy to parse and be
|
|
*fairly* human readable.
|
|
|
|
The format assignes fixed columns to each field as follows, depending on
|
|
the basic type. Beware that fields unique to a subset of objects can
|
|
overlap fields from a different type, so key off the Type field when
|
|
parsing.
|
|
|
|
Name Col N Value Format
|
|
-------- --- - ----------- ------
|
|
Name 1 13 Name left justified
|
|
Type 15 1 P type planet
|
|
Cns 17 3 Constellation 3-char IAU Abbreviation
|
|
RA 21 11 Right Ascension hh:mm:ss.ss
|
|
Dec 33 11 Declination (-)dd:mm:ss.s
|
|
Mag 45 6 Magnitude mmm.mm
|
|
Size 52 4 Size, arcseconds ssss
|
|
HeLong 57 9 Heliocentric Long ddd:mm:ss
|
|
HeLat 67 9 Heliocentric Lat (-)dd:mm:ss
|
|
EaDst 77 6 Earth distance, AU %6.3f
|
|
SnDst 84 6 Sun distance, AU %6.3f
|
|
Phs 91 3 % illumination percent 0..100
|
|
*HA 95 11 Hour Angle (-)hh:mm:ss.s
|
|
*Alt 107 9 Altitude (-)dd:mm:ss
|
|
*Az 117 9 Azimuth, E of N ddd:mm:ss
|
|
*RiseTm 127 5 Rise time, UTC hh:mm
|
|
*RiseAz 133 6 Rise Azimuth ddd:mm
|
|
*TransTm 140 5 Transit Time hh:mm
|
|
*TransAlt 146 5 Transit Altitude dd:mm
|
|
*SetTm 152 5 Set Time hh:mm
|
|
*SetAz 158 6 Set Azimuth ddd:mm
|
|
|
|
Name 1 13 Name left justified
|
|
Type 15 1 p type parabolic
|
|
[remaining same as P]
|
|
|
|
Name 1 13 Name left justified
|
|
Type 15 1 e type elliptical
|
|
[remaining same as P]
|
|
|
|
Name 1 13 Name left justified
|
|
Type 15 1 h type hyperbolic
|
|
[remaining same as P]
|
|
|
|
Name 1 13 Name left justified
|
|
Type 15 1 f type fixed
|
|
Cns 17 3 Constellation 3-char IAU Abbreviation
|
|
RA 21 11 Right Ascension hh:mm:ss.ss
|
|
Dec 33 11 Declination (-)dd:mm:ss.s
|
|
Mag 45 6 Magnitude mmm.mm
|
|
Size 52 4 Size, arcseconds ssss
|
|
C 57 1 Classification code A
|
|
Sp 59 2 Spectral classification A2
|
|
^MnAx 86 4 Minor axis diam, asecs ssss
|
|
^PA 91 3 Pstn angle, degs E of N 0..360
|
|
*HA 95 11 Hour Angle (-)hh:mm:ss.s
|
|
*Alt 107 9 Altitude (-)dd:mm:ss
|
|
*Az 117 9 Azimuth, E of N ddd:mm:ss
|
|
*RiseTm 127 5 Rise time, UTC hh:mm
|
|
*RiseAz 133 6 Rise Azimuth ddd:mm
|
|
*TransTm 140 5 Transit Time hh:mm
|
|
*TransAlt 146 5 Transit Altitude dd:mm
|
|
*SetTm 152 5 Set Time hh:mm
|
|
*SetAz 158 6 Set Azimuth ddd:mm
|
|
|
|
* Only if outputmode includes 2 or 4 (requires lat/long/elev with input)
|
|
^ Blank unless Class is G or H for galaxy.
|
|
|
|
For RCS Only -- Do Not Edit
|
|
@(#) $RCSfile: README,v $ $Date: 2003/12/05 06:27:38 $ $Revision: 1.6 $ $Name: $
|