% @(#)computbary.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:20 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1992 European Southern Observatory
%.IDENT      computbary.hlq
%.AUTHOR     DB, IPG/ESO
%.KEYWORDS   MIDAS, help files, COMPUTE/BARYCORR
%.PURPOSE    On-line help file for the command: COMPUTE/BARYCORR
%.VERSION    1.0  02-JUL-1990 : Creation, DB
%.VERSION    1.1  02-SEP-1992 : Change to eastern longitude, PJG
%----------------------------------------------------------------
\se
SECTION./BARY
\es\co
COMPUTE/BARYCORR				10-OCT-1995  DB
\oc\su
COMPUTE/BARYCORR date UT alpha delta [longitude] [latitude]
COMPUTE/BARYCORR table.tbl [longitude] [latitude]
COMPUTE/BARYCORR image alpha delta [longitude] [latitude]
	correct universal times and radial velocities to center of sun or 
	barycenter of solar system
\us\pu
Purpose:     
             Correct universal times and radial velocities to center of
             sun or barycenter of solar system .
\up\sy
Syntax:      
             a) COMPUTE/BARYCORR date UT alpha delta [longitude] [latitude]
             b) COMPUTE/BARYCORR table.tbl [longitude] [latitude]
             c) COMPUTE/BARYCORR image alpha delta [longitude] [latitude]
\ys\pa
             date = year,month,day
\ap\pa
             UT = universal time (hour,min,sec)
\ap\pa
             alpha = right ascension (hour,min,sec)
\ap\pa
             delta = declination (degree,min,sec)
\ap\pa
             longitude = EAST longitude of observatory (degree,min,sec),
\\
                         default: -70,43,55.35 (= Schmidt telescope, La Silla)
\\
                         must be negative !
                         NOTE: Eastern longitudes are used conforming to IAU.
\ap\pa
             latitude = of observatory (degree,min,sec), defaulted to
                        -29,15,25.8 (= Schmidt telescope, La Silla)
\ap\pa
             table = name of table with the following columns:
\\
                     :AHR, :MIN, :ASEC     right ascension of object
\\
                     :DDEG, :DMIN :DSEC    declination of object
\\
                     :YEAR :MONTH :DAY     date of observation
\\
                     :UTHR :UTMIN :UTSEC   UT of observation
\ap\pa
             image = name of image, then the date is taken from double prec.
                     descriptor O_TIME(1,2,3) and the UT from O_TIME(5)
                     of that image
\ap\pa
             longitude = EAST longitude of observatory (degree,min,sec)
                         default: -70,43,35.55 (= Schmidt telescope, La Silla)
                         NOTE: Eastern longitudes are used conforming to IAU.
\ap\pa
             latitude = of observatory (degree,min,sec), defaulted to
                        -29,15,25.8 (= Schmidt telescope, La Silla)

\ap\no
Note:        
             Reference:  P. Stumpff, A\&A Suppl. Ser. 41, pp. 1-8 (1980)
\\
             All times, dates, and coordinates are of type REAL so that,
             e.g., the date can also be entered as 1987.787,0,0 or just
             1987.767 . However, parameters must not be combined. That is,
             in the example given, the fraction of the year may contain
             only the number of elapsed full days, not also UT. 
             The same applies to table input, however all input
             columns must be present even if they contain only zeros. The
             minus sign for negative values may occur in any field.
\\
             a)+ b) Output: will be written to the following keywords:
\\
             OUTPUTD/D/1/1  barycentric correction to time (days)\\
             OUTPUTD/D/2/1  heliocentric correction to time (days)\\
             OUTPUTR/R/1/1  barycentric correction to radial velocity (km/s)\\
             OUTPUTR/R/2/1  heliocentric correction to radial velocity (km/s)\\
\\
             b) Output: the following table columns will be created or updated:
\\
             :BCT        barycentric correction time\\
             :HCT        heliocentric correction time\\
             :EBRV       earth's barycentric radial velocity\\
             :EHRV       earth's heliocentric radial velocity\\
             :EDV        earth's diurnal velocity (already included in
                         EBRV and EHRV)\\
\\
             (Note that the table option is very slow.)
\\
             For the ultimate accuracy, it will be necessary to precess
             (command COMPUTE/PRECESS) the coordinates to the date of the
             observation.
\\
             In order to correct measured RV's and JD's, the corrections need
             to be added as they are, i.e. taking into account their signs.
\\
             Eastern longitudes are positive and western counted
             negative conforming to IAU recommendations.
\\
             To enable automatic distinction between tables and images by the
             command, you should enter the name with the file type (extension),
             e.g. name.tbl or name.bdf. If no file type is given we default to
             a table, i.e. we use `name.tbl' .
\on\exs
Examples:
\ex
             COMPUTE/BARYCORR  obslist.tbl  155,28.3 19,49.6
               Compute corrections to UT's and RV's of observations obtained
               on Mauna Kea, Hawaii
\xe\ex
             COMPUTE/BARY  1987,12,24  1,39,10  6,44,35.8  -16,41,56
               Compute corrections to UT's and RV's of observations of Sirius
               obtained at La Silla on Xmas eve 1987
\xe\ex
             COMPUTE/BARYCORR  obsfile.bdf 6,44,35.8  -16,41,56
               Compute corrections to UT's and RV's of observations of Sirius
               obtained at La Silla; date and UT are taken from descriptor
               O_TIME of `obsfile.bdf'.
\xe \sxe