THE OBSERVATION SECTION
    
    The  observation  section  is used to assign names to columns in the
    observations files, and to optionally, associate error columns  with
    the named columns.

    The  observations  section  begins  with  the  keyword  observation, 
    followed by any number of name and error (name) column associations.
    
    Syntax
        observation
        
        name number
        
        error(name)  number
    
    The first declaration creates a name column number association.   It
    consists  of  a  name  followed by a column number. The name becomes
    the variable name for that column.
    
    The  second  declaration  creates  an  error  (name)  column  number 
    association.   It  starts with the keyword error, followed by a name
    in brackets, and a column number.  The name must be the name  of  an
    input  column  previously  declared in the observation section.  The
    error declarations are optional.
    
    The column number must be a decimal integer greater two,  since  the
    first  column  of  the  observations file is reserved for a matching
    name.  This name is used to match objects in the  observations  file
    with objects in the catalog file.
    
    Example
        # Sample observation section for the UBV system.
        
        observation
        
        u           2
        error(u)    3
        b           4
        error(b)    5
        v           6
        error(v)    7
        x           8