1 BAD_CHANNEL
          BAD_CHANNEL [List]

     Update the Bad  Channel  List  for  the  current  backend  number
(command BACKEND_NUM).  The arguments may be :

     1.  NONE to empty the list

     2.  n1 n2 ...  to insert channels n1, n2, ...  in the list

     3.  -n1 -n2 ...  to remove channels n1, n2, ...  from the list

Without arguments, BAD displays the current list
1 CALIBRATE
          CALIBRATE

     CALIBRATE zeroes the current gain array.  A new gain  array  will
be  computed  from  the data read by one or several SUBSCAN /CALIBRATE
commands ; this gain array will be locked by the next COMPUTE  command
(see these commands).
1 COMPUTE
          COMPUTE [N]

     COMPUTE divides the current signal  array  by  the  current  gain
array  and multiply by the correct calibration factor TCAL to obtain a
spectrum.

         This TCAL is computed using the standard choper-wheel formula
depending  on  the  temperatures of CHOPPER and ATMOSPHERE, as well as
the  current  optical  depths  TAU_SIGNAL  and  TAU_IMAGE,   and   the
efficiencies  BEAM_EFF  and  FORWARD_EFF.   See  the SUPPLY command to
enter values for these, and note that BEAM_EFF should  not  be  higher
than FORWARD_EFF.

         N is the backend number; its default is the  value  specified
in the BACKEND_NUM command.  The number of channels will depend on the
backend configuration ; two spectra may be obtained if the backend was
split (see the BACKEND_NUM command).

         The computed spectrum may be further be analysed by  standard
LAS commands
1 DIRECTORY
          DIRECTORY name

     Define the directory where the raw data  are.   Default  is  your
current  working  directory.   Use "*" as argument to process files at
Pico-Veleta.  This will take into account the specific organisation of
the tree directories.
1 GAINS
          GAINS [N]

     Plot the current gain values.  The gains will be those of Backend
number  N  or  by  default  the  backend  specified  by the BACKENDNUM
command.
1 Language
          CAL\ Language Summary
BACKEND_NUM     : Choose a backend.
BAD_CHANNEL     : Update the Bad Channel List.
CALIBRATE       : Start a new calibration.
COMPUTE [N]     : Compute a spectrum from the current signal and
gains.
DIRECTORY [name]: Define the directory where the raw data are.
GAINS [N]       : Plot the current gain values.
SAVE [name]     : Saves the current parameters.
SUPPLY          : Define a calibration parameter.
SHOW            : Displays the current parameters.
SIGNAL          : prints out the current signal array.
SCAN_NUM N       : Process a new scan.
SUBSCAN         : Read a subscan.
1 SAVE
          SAVE name

     SAVE creates a procedure file of name "name.pro", containing  all
the  current  parameters of the program.  This file may be executed at
any time using the @ command :  just type  "@  name"  after  the  LAS>
prompt,  pass  "@ name" as a parameter when calling LAS.  This file is
composed of standard LAS, ANALYSE and CAL commands, and may be  edited
with the EDT editor of DCL.
1 SCAN_NUM
          SCAN_NUM [n]

     Reset the scan number to  n  AND  initialise  the  signal  array.
Subscans may then be read in by the SUBSCAN /SIGNAL command.
1 SHOW
          CAL\SHOW [Arg]

     Displays the specified CAL parameter.  If Arg  is  ALL,  all  CAL
parameters  will be listed.  Note that you should specify the language
because this command is ambiguous with the LAS\SHOW command.
1 SIGNAL
          SIGNAL

     Type the current signal array (for debugging only).
1 SUBSCAN
          SUBSCAN [n] [/SIGNAL w1 w2 [..]] [/CALIBRATE c1 c2 [...]]
               [/COLD f1 f2 [...]]

     Read the subscan number N of the current scan.  By default, n  is
the  current  subscan  number incremented by one.  The options control
which array (ATMOSPHERE, CHOPPER and COLD) is  to  be  increment,  and
with  which  gains.  These arrays are used in COMPUTE to determine the
receiver and system temperatures, and the  atmospheric  parameters  if
SUPPLY  CAL AUTO has been previously entered (effective only between a
CALIBRATE and a COMPUTE  command).   The  program  will  automatically
process all line backends connected at the time of observations.

2 /SIGNAL
          SUBSCAN/SIGNAL w1 w2 ...

     Increment the signal array by the weighted sum of  the  available
phases in this subscan, with weights w1, w2, ...
2 /CALIBRATE
          SUBSCAN/CALIBRATE c1 c2 ...

     Increment the current gain array  by  the  weighted  sum  of  the
available  phases  in  this  subscan,  with  weights c1, c2, ...  Also
increment the ATMOSPHERE mean value by  the  average  of  phases  with
negative  weights, and the CHOPPER mean value by the average of phases
wit negative weights.
2 /COLD
          SUBSCAN/COLD f1 f2 ...

     Increment the COLD load mean value by the  weighted  sum  of  the
available phases in this subscan, with weights f1, f2, ...
1 SUPPLY
          SUPPLY something [value1 [value2 [...]]] [/RECEIVER i]

     This is a command to introduce calibration parameters as well  as
observation  parameters that were not included in the header (if any).
The /RECEIVER option specifies the receiver for which the parameter is
valid.
        
AMBIENT temp pressure   : ambient temp.(K) and pressure (mbar)
ATMOSPHERE sig img      : atmospheric temperature (absorbing
                          layers), in both sidebands 
EFFICIENCY beam forward : antenna beam efficiency,
                          and forward (sky) efficiency
CAL     AUTO            : parameters are normally reset automatically,
        MANUAL            or only by SET command
CHOPPER hot cold        : chopper temperature hot (or ambient)
                          and cold (liquid N2)
TAU sig img             : opt.depth in Signal and Image Bands
LINE name               : enters a name for the observed line (useful
                          for bookeeping purposes).
