
1 ATMOSPHERE
        [ASTRO\]ATMOSPHERE [INTERPOLATE|MAKE|SAVE] [/PRINT]

    Compute  atmospheric emission, opacity, system temperatures, etc..., us-
    ing input parameters provided by the user. Input parameters are the fol-
    lowing SIC variables:
       TEMPERATURE      Outside temperature
       ZERO_PRESSURE    Pressure at sea level.
       AIRMASS          Number of air masses
       WATER            Precipitable water vapor
       FORWARD_EFF      Forward efficiency
       GAIN_IMAGE       Receiver gain ratio
       TREC             Receiver temperature
       FREQ_SIG         Signal frequency (in GHz)
       FREQ_IMA         Image frequency (in GHz)
    These  variables  can  be assigned using the SIC command LET.  The addi-
    tional input variables
       ALTITUDE         Site altitude
       FREQ_SIG         Signal frequency (in GHz)
       FREQ_IMA         Image frequency (in GHz)
    are modified by the ASTRO OBSERVATORY and LINE commands.
    Option /PRINT displays all these inputs.

    The output of the command consists in the following variables
       TRUE_PRESSURE    Local pressure, derived from the site altitude and
                        the sea level pressure by the scale height of 5.5 km.
       TSYS             The system temperature in the signal sideband
       TAU_H2O          The water vapor opacity
       TAU_O2           The dry atmosphere opacity (mostly due to Oxygen,
                        but minor constituents like Ozone may also play a role)
       TAU_TOT          The total opacity: H2O + O2 (+ minor components for
                        new ATM versions)
       EMIS_SIG         The atmospheric emission (Kelvin) in the signal sideband
       EMIS_IMA         The atmospheric emission (Kelvin) in the image sideband
       PATH_SIG         The atmospheric excess optical path length (mm)
                        in the signal sideband
       PATH_IMA         The atmospheric excess optical path length (mm)
                        in the image sideband
    These variables can then be used to produce plots of atmospheric  trans-
    parency, system temperatures, etc...

    ATMOSPHERE INTERPOLATE
    will do the same calculations, but interpolating the data from the bina-
    ry table (logical name GAG_ATMOSPHERE).

    ATMOSPHERE MAKE filename nf freqmin freqmax
    will create the binary table filename.bin  for  nf  frequencies  between
    freqmin and freqmax (in GHz).

    ATMOSPHERE SAVE filename
    will  save  inside  filename.bin  the  binary table currently in memory.
    This is useful to save with the current machine byte order a table  pre-
    viously computed on a different machine with a different byte order.

1 CATALOG
        [ASTRO\]CATALOG name [/VELETA] [/ALTERNATE]

    Open  the  catalog  file  specified by 'name'. Default file extension is
    sample.sou and phase.sou (an incomplete list of Plateau  de  Bure  phase
    calibrators).  The  file GAG_DATA:phase-pdb.sou contains a more complete
    list of Plateau de Bure phase calibrators.

    CATALOG with no arguments will display the  catalogs  currently  opened.
    Please  enter HELP CATALOG FORMAT for a description of the catalogs con-
    tent.

2 /VELETA
        This option will open the catalog file 'name'.CAT, assuming it  fol-
    lows  the  format of OBSINP catalogs in use on the 30m Radiotelescope of
    IRAM.  A file 'name'.SOU will be created in the current directory in the
    Plateau  de  Bure format, so that this option needs to be specified ONLY
    ONCE for each catalog. Fancy options such as SL0P, SB0P ... are not sup-
    ported.

2 /ALTERNATE
        This option will open the specified catalog as a second catalog, on-
    ly accessible through the "/ALTERNATE" options of commands SOURCE, HORI-
    ZON,  and  CONVERT.  For  instance,  a catalog containing calibration or
    pointing sources may be opened as an Alternate catalog,  while  the  ob-
    jects  to study are kept in the Current catalog, enabling easy switching
    between the two kinds of objects.

2 FORMAT

        In the ASTRO catalog format each source uses one line of the catalog
    file.  Each line should contain the following consecutive keywords (some
    may be omitted):
     1) Source name field:
        The source name field is a composite item which can accomodate several
        names for a single source. Names should be separated by a vertical bar
        ( | ) with no embedded spaces, e.g.: B0415+379|3C111. Each name must
        have at most 12 characters.
     2) Coordinate system: 2 characters, optional, may be:
          EQ for equatorial coordinates. If "EQ" is given explicitely,
                                 then the Epoch  keyword is mandatory.
          GA for Galactic II coordinates.
          EC for J2000 Ecliptic coordinates
          HO for horizontal coordinates
          DA for equatorial, present-day coordinates.
     3) Epoch:  needed for equatorial coordinates after "EQ" keyword.
     4) Longitude-like coordinate: in degrees, except for EQ and DA where it
        should be in hours. Format is
              hh:mm:ss.sss[,first[,second]]
        where
              "hh:mm:ss.sss" is a generalized sexagesimal format
                (hh:mm:ss.sss or dd.ddd or hh:mm.mmm)
              "first" is an (optional) first order time derivative
              "second" is an (optional) second order time derivative
     5) Latitude-like coordinate: in degrees, same format as above.

     The following OPTIONAL KEYWORD can also be included, and may be listed in
     any order:

     A) a "Velocity" keyword
         Velocity Value
            where "Velocity" is an alphabetic code, equal to "LSR", "HELIO"
            or "EARTH". HELIO actually means: referred to the Solar System
            barycenter. Value is the velocity in km/second, in the corresponding
            reference frame. Default is zero.
     B) an "Intensity" keyword
         FLUX  Value [Index]
             Value is the flux in Jy. Index is an optional spectral index
         Mx  Value
             Value is the magnitude, Unknown values can be coded 99.99
             Mx can be MAGNITUDE, or x is one of V,R,I,J,H,K,L,M,N to indicate
             the visual band
     C) a "Project" keyword
         PROJECT ProjectID
            to specify a project identification (a string without spaces)
     D) an "hour" keyword to indicate the validation hour for the coordinates
        (which is useful when time  derivatives are given), specified by
         HOUR Value
     E) A "Parallax" keyword
         PARALLAX Value
              Value is in arcsec.

    Any other keyword will be ignored.

1 CONSTELL
        [ASTRO\]CONSTELL [/DRAW [m] [l] [s]] [/BOUNDARIES]

    Plots in the current FRAME with the current FONT, MARKER  and  PEN,  the
    constellations, i.e., the main stars of all constellations with a marker
    size adequately depending on the magnitude.  The options are:
     /DRAW [m] [l] [s]
     "m" will cause markers at the star's positions to be plotted
     "l" will cause the constellations outlines to be plotted
     "s" will cause the star's names to be plotted (using current centering and
         character size)
     /BOUNDARIES will draw the constellation boundaries (originally constant RA
         and DEC at 1875 epoch, they are precessed to the current epoch).
         The current code is quite slow.

    The default is CONSTELL /DRAW m l. This command makes use of the logical
    name  GAG_CONSTELL  which  points to a GILDAS Table containing the stars
    positions (constellation.bin bydefault) and drawing codes, and  GAG_CON-
    ST_BOUND which defines the constellation boundaries (file sky.bin by de-
    fault).

1 CONVERT
        [ASTRO\]CONVERT  [Catalog_Name]  [/ALTERNATE]  [/J2000  [Obs_epoch]]
    [/PRECESS  [New_epoch]]  [/GALACTIC] [/FLUX fmin] [/NAME ncname [iname]]
    [/INPUT POS|FLUX filename pos]

    Change catalog format or epoch.

    Without any option (or with option  /ALTERNATE)  and  without  argument,
    this command creates an OBSINP-compatible copy of the 'name'.SOU catalog
    (or Alternate  catalog  if  /ALTERNATE  is  specified)  under  the  name
    'name'.CAT.

    With  the  /J2000  and/or  /PRECESS option, the command will precess the
    current SOU catalog to J2000 system, using the specified epochs for  ob-
    servation (Obs_epoch, default 1950) and final result (New_epoch, default
    2000). The output catalog is 'Catalog_name'.SOU, and  has  the  standard
    format.

    /FLUX  create  a  copy  of the current catalog with only sources of flux
    larger than fmin

    /NAME ncname [iname]: reserve ncname characters for names  field.   With
    iname.gt.0, a standard name (Jhhmmmsddmmm) is created and put in inameth
    positions in the list of names.

    /INPUT FLUX filename : will take fluxes from filename, which has  itself
    the format of a catalog (both input catalog and filename are assumed al-
    phabetically sorted)

    /INPUT POSITION filename dpos : will take positions  from  filename,  if
    different  by more than dpos arc seconds. Filename has itself the format
    of a catalog (both input catalog and filename are assumed alphabetically
    sorted)

    /ALTERNATE option : do the same operation with the Alternate catalog.

1 FRAME
        [ASTRO\]FRAME System [...]

    This command specifies the reference frame to be used for plots.  System
    may be HORIZONTAL or EQUATORIAL (at epoch defined by TIME command) If no
    other  argument  is  given,  plotting is done in rectangular coordinates
    representing Azimuth-Elevation or Right Ascension-Declination.  If other
    arguments are given, a Stereographic projection is used:
      - FRAME EQUATORIAL Ra Dec Size
        the  projection  will  be  centered on Ra and Dec (hours - degrees);
        Size in degrees specify the plotting range (e.g.  180  for  a  whole
        hemisphere = the default).
      - FRAME HORIZONTAL Az El Size
        same thing, but Az and El are in degrees.
      - FRAME HORIZONTAL Center
        will  plot  a  hemisphere  in horizontal system, where Center may be
        ZENITH, NORTH, EAST, SOUTH or WEST.

1 HEADER
        [ASTRO\]HEADER

    Write the UTC and LST times on top of the FRAME plot, as well as the ob-
    servatory coordinates.

    The  same  information,  as  well  as a couple of other parameters (.eg.
    twilight start and end), are listed in the  ASTRO  terminal.  Output  is
    something like:
      UTC :    19-SEP-2007   02:18:59.998
      UT1 :    19-SEP-2007   02:18:59.698    DUT1 :     -0.300
      TDT :    19-SEP-2007   02:20:05.182    DTDT :     65.184
      Julian date :          2454362.60
      LST :        02:33:06.1453

      OBS :    BURE   05:54:28.500   44:38:02.000
      Alt.:    2.560 km     Sun Avoidance:    45.0 deg.

      SunRise/Set :      05:23:47.980   17:37:02.472
      Twilight              Start          End
      Civil :            18:10:55.799   04:49:54.653
      Nautical :         18:45:21.460   04:15:28.992
      Astronomical :     19:20:49.604   03:40:00.848

1 HORIZON
        [ASTRO\]HORIZON  h1  h2 ... [/AIRMASS] [/SOURCE ... ] [/PLANET ... ]
    [/FLUX Fmin Fmax] [/NIGHT_MARKS] [/ALTERNATE] [/PROJECT] [/ELEVATION]

    This command is used to produce plots of LST  ranges  of  observability,
    above specified elevations, of sources and planets. An OBSERVATORY and a
    TIME must have been selected. The LST axis is drawn on the bottom of the
    plot,  and UTC on the top . An horizontal line is drawn for the time pe-
    riod during which the object(s) is(are) visible above elevation h1; tick
    marks  and  labels are provided for elevations h1, h2, ... (in degrees),
    or corresponding air masses values  (with  /AIRMASS  option).  Elevation
    values must be in increasing order, or airmasses in decreasing order.

    Various options are available to control the plot:
        /SOURCE                  will plot all sources
                                 of the current (by default) or alternate
                                 (if /ALTERNATE is used) catalog.
        /SOURCE name1 name2 ...  will be restricted to the specified sources
        /SOURCE NEXT n           will plot the next n sources in the current
                                 catalog (repeat this command to avoid over-
                                 crowded pages)
        /ALTERNATE               with /SOURCE, will use the Alternate catalog
        /FLUX Fmin Fmax          restrict the search to sources with flux in
                                 the specified range.

        /PLANET                  will plot on one page all solar-system bodies
        /PLANET name1 name2 ...  will be restricted to the specified bodies

        /NIGHT_MARKS             Plots also the beginning and end of astronomical,
                                 nautical and civil twilights, and an estimate of
                                 the moon phase and the moon bolometric magnitude.

    For  specific  Plateau de Bure scheduling purposes, the options /PROJECT
    and /ELEVATION can be used to further restrict the search of the sources
    in  the  catalog. In that case, the source catalog must have a number of
    additional parameters available for each source (project name,  frequen-
    cy, priority, minimal elavation,...).

1 Language
                        ASTRO\ Language summary

    ATMOSPHERE          : compute atmospheric parameters
    CATALOG             : opens a standard source catalog
    CONVERT             : precess coordinates from an input catalog
    CONSTELL            : draws constellation on current plot
    FRAME               : define plotting reference system
    HORIZON             : plot observability hours of sources and planets
    HEADER              : write time parameters on top of plot
    OBSERVATORY         : define observatory coordinates
    PLANET              : compute planet coordinates
    SET parameter value : enter some parameter value
    SOURCE              : compute source coordinates
    TIME                : set computation time
    UV_TRACKS           : plot interferometer UV tracks

1 OBSERVATORY
        [ASTRO\]OBSERVATORY [longitude latitude altitude [radius]]
                 or
        [ASTRO\]OBSERVATORY [Name]

    Specify  an observatory by giving its geographic coordinates in degrees,
    and elevation in km above sea level. Caution: east longitudes are  posi-
    tive.  The fourth argument is the radius of the Sun avoidance circle, in
    degrees (default is 30 degrees).

    Example:  OBSERVATORY 44:23:12.0 +45:09:57.9 3.987 30.

    A number of observatories are pre-defined and can be  selected  directly
    be typing "OBSERVATORY Name". Type "OBSERVATORY ?" for the list of known
    telescopes.

    Without argument, the observatory name is translated  from  the  GAG_AS-
    TRO_OBS logical name.

1 PLANET
        [ASTRO\]PLANET [name] [/DRAW [argument]] [/QUIET]

    Compute  the  coordinates  of  a Solar System object. Known objects are:
    MOON, SUN, MERCURY, VENUS, MARS, JUPITER, SATURN, URANUS, NEPTUNE. If no
    name  is  entered, all objects are selected. The Option /DRAW is used to
    plot the object symbol on the screen.

    The PLANET command output the planet coordinates (apparent RA,  apparent
    DEC,  Azimuth and Elevation at time of computation) and the sun distance
    (with a warning message if this distance os  lower  than  the  telescope
    limit).  PLANET also indicates the geocentric (DE) and heliocentric (DS)
    distances of the object (in AU), the apparent minor and major  diameters
    (Min and Maj in arcsec), the position angle of the central meridian (PA,
    east from north, in degrees), the brightness temperature (TB in K),  the
    flux  (S  in  Jy)  at the current frequency, the frequency (in GHz), the
    beam (in arcsec), the main beam temperature (Tmb in K),  the  associated
    flux (in Jy) and the planet size convolved with the telescope beam (size
    in arcsec).  The frequency can be entered by updating the variable  FRE-
    QUENCY  (in  GHz). The beam used in computation is available through the
    READONLY variable PRIMBEAM (in arcsec). User may  override  the  default
    used beam size by setting the BEAM variable to a non-zero value (in arc-
    sec).

    All these parameters are also also written in SIC variables, in the  AS-
    TRO%PLANET%  structure.  Just  enter EXAMINE ASTRO%PLANET% to get a com-
    plete list of these variables. PLANET /QUIET suppresses all  the  print-
    outs on the screen.

    Arguments to PLANET /DRAW may be LINE, MARKER, SYMBOL, or FULL:
      LINE   will draw a line from the previously computed position
      MARKER will draw a marker (GreG style defined by GREG\SET MARKER)
              at the computed position
      SYMBOL will draw the planet's symbol at the computed position
      FULL   will combine MARKER and SYMBOL (the symbol will be offset
             one marker size above the computed position).
    Default  is  SYMBOL. If several arguments are given they will be used in
    sequence.

1 SET
        [ASTRO\]SET parameter value

    Enter a value for a parameter. Valid parameters are :
      - DUT1
        which is (UT1-UTC) in seconds of time (from I.E.R.S.)
      - DTDT
        which is (TDT-UTC) in seconds of time (from I.E.R.S.)
      - AZIMUTH_REFERENCE
        which is either NORTH or SOUTH, and defines the azimuth to  be  zero
        in the North or South direction (to conform to local conventions).
      - SET NAME Argument
        Define  the  naming convention for listing sources from the catalog.
        Sources in the catalog may have several names. This  command  define
        which  name  should be printed in commands SOURCE and HORIZON. Argu-
        ment can be
            *   to print the name of the source which has been searched for
            ALL to print all the possible names of the source
            1,2,3 etc... to print the first, second, third,  etc..  possible
            names of the source

1 SOURCE
        [ASTRO\]SOURCE  [name  [...]] [/DRAW [argument]] [/ALTERNATE] [/SUN]
    [/FLUX Fmin Fmax]

    Compute the coordinates of a source from the current catalog (or the al-
    ternate catalog, if the option /ALTERNATE is used). If no name is speci-
    fied, all sources of the catalog are selected.  Source  coordinates  may
    also  be  directly  specified in the command line, in the same format as
    the catalog file. The /DRAW option is used to draw the  source  name  on
    the plot at its current position (Azimuth, Elevation).

    The  source  coordinates  (azimuth and elevation at time of computation)
    are printed on the screen, as well as the  line-of-sight  components  of
    the following velocities:
      - V(S/OBS)
        Source (S) relative to Observatory
      - V(S/LSR)
        Source  (S)  relative to Local Standard of Rest. This is the LSR ve-
        locity furnished by the observer as part of the source  coordinates.
      - V(LSR/G)
        Local Standard of Rest relative to Solar System Barycenter (G)
      - V(G/OBS)
        Solar System Barycenter (G) relative to the Observatory
    All velocities are in km/s, positive if the distance is increasing. With
    the above convention, V(S/OBS) = V(S/LSR)+V(LSR/G)+V(G/OBS). Coordinates
    and velocities are written in SIC variables, in the ASTRO%SOURCE% struc-
    ture (just type EXAMINE ASTRO%SOURCE% to get the complete list).

    The output of the SOURCE command can be modified with the following  op-
    tions:  SOURCE  /SUN  will  also  list  the sun avoidance limits; SOURCE
    /PRINT suppresses the printing of Azimuth, Elevation, and the velocities
    and prints the source properties as in catalog; SOURCE /QUIET suppresses
    all printout (useful to avoid too many messages on the screen in e.g.  a
    loop on many sources).

    SOURCE  /FLUX  Fmin Fmax will select only sources with flux densities in
    the specified range. Marker sizes will be proportional to the (logarithm
    of  the) flux. This is useful to, e.g., filter a list of potential cali-
    brators.

    Arguments to SOURCE /DRAW may be LINE, MARKER, SYMBOL, or FULL,  as  for
    command PLANET:
      LINE   will draw a line from the previously computed position
             (SOURCE or PLANET)
      MARKER will draw a marker (GreG style defined by GREG\SET MARKER)
             at the computed position
      SYMBOL will draw the source name in capitals at the computed position
      FULL   will combine MARKER and SYMBOL (the name will be offset
             one marker size above the computed position).
    Default  is  SYMBOL. If several arguments are given they will be used in
    sequence.

1 TIME
         [ASTRO\]TIME [time [date]] [/ZONE Z] [/UT1] [/TDT] [/NODRAW]

    Specify the time-date of computation. Time  is  normally  understood  as
    UTC; options /UT1 and /TDT may be used to change this to UT1 or TDT. The
    time format is HH:MM:SS.SSS, and the date format  is  DD-MMM-YYYY.  Time
    and date may be absent or replaced by an asterisk (*), which defaults to
    current system time.  Local civil time may be input instead of UTC, with
    the  option  /ZONE z, where z is the difference in hours between UTC and
    local civil time (use /ZONE 2 in western Europe in Summer, 1 in winter).

    By  default, if the sun is visible, a Sun Avoidance Circle (see HELP OB-
    SERVATORY) is plotted. It can be suppressed using  the  /NODRAW  option.
    Use HEADER to examine the value of the Sun Avoidance Circle.

1 UV_TRACKS
        [ASTRO\]UV_TRACKS   station1   station2  [station3  [...]]   [/FRAME
    [size]] [/HOUR_ANGLE Hmin [Hmax]] [/TABLE [Name]] [/HORIZON Elmin] [/IN-
    TEGRATION t] [/STATIONS ALL|list] [/WEIGHT Mode]

    Plot  interferometer  UV tracks as observed with the Plateau de Bure in-
    terferometer (but the command is in fact more general and  can  be  used
    with any array, especially ALMA: see bottom of this help).

    Station  coordinates  are  searched  for  in the file defined by the AS-
    TRO_STATIONS logical variable. Stations  should  be  referred  to  by  a
    mnemonic (e.g. E03, W00 ...) given as arguments of UV_TRACKS.

    The  coordinates of the most recently selected SOURCE or PLANET are con-
    sidered. Option /HORIZON specifies a minimum elevation (in degrees)  for
    the  source. Option /HOUR_ANGLE can be used to limit the hour angle cov-
    erage. Default is from source rise  (above  the  minimum  elevation)  to
    source setup; Hmin and Hmax are in hours.  The frequency of the simulat-
    ed observation is read in the FREQUENCY SIC variable (which is also used
    by several other commands in ASTRO).

    UV_TRACKS  can be used iteratively, to simulate the observations of sev-
    eral configurations. Option /FRAME [size] should be used to start a  new
    UV  coverage. It clears the plot, draws the box, and open a new table if
    /TABLE is present. 'size' is the maximum UV spacing plotted,  in  meters
    (default  800  m).  Subsequent call to the command (without /FRAME) adds
    the new configurations. The user may select another color  pen  to  dis-
    tringuish  between the various coverages. A sketch of the interferometer
    described by ASTRO_STATIONS is also drawn, and the selected stations/an-
    tennas are highlighted.

    Option  /TABLE  can be used to write the sampling function (UV coverage)
    in a UV table for further processing such as producing beams  using  the
    task  UV_MAP.  Name  should  be specified only if option /FRAME has been
    used, to initialize the table. Subsequent call to the  UV_TRACK  command
    will  append the new observation to this table. The visibilities written
    in the UV table are constant, as if a point source were  observed  (real
    part  = 1, imaginary part = 0). The weight is by default constant, equal
    to 1. This can be modified using the /WEIGHT Mode option.  Mode  can  be
    UNIFORM (constant weight) or AIRMASS (weight proportional to airmass^-2,
    i.e. to sin(elevation)^2).

    Option /INTEGRATION t [min] is used to change the time interval  between
    points  in the UV plane (currently there is a max of 3000 points between
    HA_MIN and HA_MAX). Default is 15 minutes per point.

    ---- Notes for experts ----

    Option /STATIONS enable to access stations by their rank number  in  the
    ASTRO_STATIONS  file, rather by their mnemonic. ALL means 'take all sta-
    tions'. Switching between files describing interferometer  stations  can
    be  done  inside ASTRO by redefining the ASTRO_STATIONS logical variable
    using the command
    SIC LOG ASTRO_STATIONS "path/to/the/desired/file"
    The BURE stations are described in the file ephemeris/astro_stations.dat
    (and accessed by default on most ASTRO installs, or otherwise by
    SIC LOG ASTRO_STATIONS GAG_ASTRO_DATA:astro_stations.dat)

    ---- Using UV_TRACKS for ALMA ----

    UV_TRACKS can be used to simulate ALMA observations, using the very same
    options as described above (e.g. to create tables with  one  or  several
    configurations). To do so, the command sequence must be

    observatory alma
    sic log astro_stations "alma-cycle1-1.cfg"
    uv_track all [...options...]

    The  logical  astro_stations must point to a configuration file of ALMA.
    They are  distributed  with  GILDAS  and  are  called  "alma-cycle0-com-
    pact.cfg"   and   "alma-cycle0-extended.cfg"   for  Cycle  0;  "alma-cy-
    cle1-*.cfg" (6 different configurations) and "aca-cycle1.cfg" for  Cycle
    1.  Then "uv_track all" means all stations will be used. This is differ-
    ent from Bure, where all stations are in one single file  and  the  user
    defines  with  uv_track which stations are to be used; but this would be
    painful for ALMA (32 stations to enter in Cycle 1...).

    For ACA, it is better to enter "observatory aca" - coordinates  are  the
    same, but this will make sure the proper antenna diameter is used in the
    computation of shadowing.

1 ENDOFHELP







